Adjustable implant and method of use

ABSTRACT

A system includes an adjustable implant configured for implantation internally within a subject and includes a magnet configured for rotation about an axis of rotation, the magnet operatively coupled to a drive transmission configured to alter a dimension of the adjustable implant. The system includes an external adjustment device configured for placement on or adjacent to the skin of the subject having at least one magnet configured for rotation, the external adjustment device further comprising a motor configured to rotate the at least one magnet and an encoder. Rotation of the at least one magnet of the external adjustment device effectuates rotational movement of the magnet of the adjustable implant and alters the dimension of the adjustable implant Drive control circuitry is configured to receive an input signal from the encoder.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. Pat. Application No.17/644,655, filed Dec. 16, 2021, which is a continuation of U.S. Pat.Application No. 16/029,214, filed Jul. 6, 2018, now U.S. Pat. No.11,234,849, which is a continuation of U.S. Pat. Application No.14/920,709, filed Oct. 22, 2015, now U.S. Pat. No. 10,039,661; which isa continuation of U.S. Pat. Application No. 14/668,901, filed Mar. 25,2015, now U.S. Pat. No. 9,271,857, which is a continuation of U.S. Pat.Application No. 14/328,568, filed Jul. 10, 2014, now U.S. Pat. No.9,526,650, which is a continuation of U.S. Pat. Application No.13/649,977, filed Oct. 11, 2012, now U.S. Pat. No. 8,808,163, which is acontinuation of U.S. Pat. Application No. 13/158,117, filed Jun. 10,2011, now U.S. Pat. No. 8,715,159, which is a continuation of U.S. Pat.Application No. 12/259,965, filed Oct. 28, 2008, now U.S. Pat. No.7,981,025, which is a continuation of U.S. Pat. Application No.11/760,482, filed Jun. 8, 2007, now U.S. Pat. No. 7,862,502; whichclaims priority to U.S. Provisional Application No. 60/904,625, filedMar. 1, 2007, U.S. Provisional Application No. 60/854,574, filed Oct.25, 2006, and U.S. Provisional Application No. 60/853,105, filed Oct.20, 2006, each of which is incorporated by reference in its entirelyherein.

FIELD

The field of the invention generally relates to medical devices, andmore particularly, adjustable implants and methods of use.

BACKGROUND

Obesity is a common disease of unknown etiology. It is a chronic,multifactorial disease that develops from an integration of genetic,environmental, social, behavioral, physiological, metabolic,neuron-endocrine and psychological elements. This disease is considereda cause or co-morbidity to such conditions as GERD, high blood pressure,elevated cholesterol, diabetes, sleep apnea, mobility and orthopedicdeterioration, and other consequences, including those limiting socialand self-image and those affecting the ability to perform certaineveryday tasks. Since traditional weight loss techniques, such as diet,drugs, exercise, etc., are frequently ineffective with many of thesepatients, surgery is often the only viable alternative.

Body Mass Index (BMI) is the most common method used to define the obesepatient. This measurement is obtained by taking a person’s weight inKilograms (Kg) and dividing it by the square of height in meters. Basedon policies set forth by the United States National Institutes of Health(NIH), BMI is used to characterize the degree of excess weight. Thesecategories are listed in Table 1 listed below. Presently, based oncurrent NIH policy, only those people with a BMI of 35 or greaterqualify for surgical intervention.

TABLE 1 Table 1- Risk of Associated Disease According to BMI and WaistSize BMI Weight Disease Risk Disease Risk Classification Waist ≤ 40 in.(men) or 35 in. (women) Waist > 40 in. (men) or 35 in. (women) 18.5 orless Underweight - N/A 18.5-24.9 Normal ... N/A 25.0-29.9 OverweightIncreased High 30.0-34.9 Obese class 1 High Very High 35.0-39.9 Obeseclass 2 Very High Very High 40.0-49.9 Morbidly obese Extremely HighExtremely High >49.9 Super Obese Extremely High Extremely High

In the United States, more than 30% of the population is obese asdefined in Table 1, including men, women, and children There are morethan 15 million Americans (5.5%) who are morbidly obese The number ofobese children is growing at an alarmingly fast rate Surgical treatmentsfor obesity continue to be a strong focus of research due to their highlevel of effectiveness although no treatment is considered ideal. It iswell-established in the medical literature that obesity adverselyaffects general health, and can result in reduced quality of life andreduced lifespan. It is now well-accepted that obesity is associatedwith increased risk of cardiovascular disease, diabetes, and otherhealth issues. In contrast, animal studies show that longevity isincreased in lean subjects (Weindruch, R. & Walford, R. L., 1988 TheRetardation of Aging and Disease by Dietary Restriction, Thomas,Springfield, I11.; Spindler. S. R., 2003, in Anti-Aging Therapy forPlastic Surgery, eds. Kinney. B. & Carraway, J., Quality Medical, St.Louis, Mo.). Much work continues to be needed before a widely acceptablesolution can be expected.

Surgical weight loss (bariatric) procedures are designed to restrictweight gain breducesmiting caloric intake by restricting effectivestomach size or by malabsorption, which is reducing the intestine’sability to absorb nutrition. Many surgeons offer their patients acombined procedure that includes a restrictive and malabsorptionmaterial These procedures are irreversible and rely on a surgeon’sjudgment to estimate the final size of the new restrictive stomach aswell as the remaining small intestine length to provide adequatenutrition for optimal weight loss and management for the patient’slifetime.

Presently, bariatric procedures can be performed by open or laparoscopicsurgery. Open surgery typically requires a ten day hospitalization and aprolonged recovery period with a commensurate loss of productivity.Laparoscopic procedures have reduced in-hospital stay to three days,followed by a three week at-home recovery. These procedures can even beperformed as an outpatient procedure. Laparoscopic procedures havereduced cost considerably, making the minimally invasive laparoscopicprocedure available to more patients. In 2000, there were 30,000bariatric procedures performed, while in 2003, over 90,000 procedureswere reported.

One common obesity surgery is the Roux-en-Y gastric bypass (often knownonly as a “gastric bypass”). During this type of operation, the surgeonpermanently changes the shape of the stomach by surgically reducing(cutting or stapling) its size to create an egg-sized gastric pouch or“new stomach.” The rest of the stomach is then divided and separatedfrom this new stomach pouch, greatly reducing the amount of food thatcan be consumed after surgery. In addition to reducing the actual sizeof the stomach, a significant portion of the digestive tract is bypassedand the new stomach pouch is reconnected directly to the bypassedsegment of small intestine. This operation, therefore, is both arestrictive and malabsorptive procedure, because it limits the amount offood that one can eat and the amount of calories and nutrition that areabsorbed or digested by the body. Once completed, gastric bypass surgeryis essentially irreversible. Some of the major risks associated with theRoux-en-Y gastric bypass procedure include bleeding, infection,pulmonary embolus, anastomotic stricture or leak, anemia, ulcer, hernia,gastric distention, bowel obstruction and death.

Another common obesity surgery is known as vertical banded gastroplasty(“VBG”), or “stomach stapling.” In a gastroplasty procedure, the surgeonstaples the upper stomach to create a small, thumb-sized stomach pouch,reducing the quantity of food that the stomach can hold to about 1-2ounces. The outlet of this pouch is then restricted by a band thatsignificantly slows the emptying of the pouch to the lower part of thestomach. Aside from the creation of a small stomach pouch, there is noother significant change made to the gastrointestinal tract. So, whilethe amount of food the stomach can contain is reduced, the stomachcontinues to digest nutrients and calories in a normal way. Thisprocedure is purely restrictive; there is no malabsorptive effect.Following this operation, many patients have reported feeling full butnot satisfied after eating a small amount of food. As a result, somepatients have attempted to get around this effect by eating more or byeating gradually all day long. These practices can result in vomiting,tearing of the staple line, or simply reduced weight loss Major risksassociated with VBG include unsatisfactory weight loss or weight regain,vomiting, band erosion, band slippage, breakdown of staple line,anastomotic leak, and intestinal obstruction

A third procedure, the Duodenal Switch, is less common. It is amodification of the biliopancreatic diversion or “Scopinaro procedure.”While this procedure is considered by many to be the most powerfulweight loss operation currently available, it is also accompanied bysignificant long-term nutritional deficiencies in some patients. Manysurgeons have stopped performing this procedure due to the seriousassociated nutritional risks

In the Duodenal Switch procedure, the surgeon removes about 80% of thestomach, leaving a very small new stomach pouch. The beginning portionof the small intestine is then removed, and the severed end portions ofthe small intestine are connected to one another near the end of thesmall intestine and the beginning of the large intestine or colon.Through this procedure a large portion of the intestinal tract isbypassed so that the digestive enzymes (bile and pancreatic juices) arediverted away from the food stream until very late in the passagethrough the intestine. The effect of this procedure is that only a smallportion of the total calories that are consumed are actually digested orabsorbed. This irreversible procedure, therefore, is both restrictive(the capacity of the stomach is greatly reduced) and malabsorptive (thedigestive tract is shortened, severely limiting absorption of caloriesand nutrition). Because of the very significant malabsorptive materialof this operation, patients must strictly adhere to dietary instructionsincluding taking daily vitamin supplements, consuming sufficient proteinand limiting fat intake. Some patients also experience frequent largebowel movements, which have a strong odor. The major risks associatedwith the Duodenal Switch are bleeding, infection, pulmonary embolus,loss of too much weight, vitamin deficiency, protein malnutrition,anastomotic leak or stricture, bowel obstruction, hernia,nausea/vomiting, heartburn, food intolerances, kidney stone or gallstoneformation, severe diarrhea and death.

One relatively new and less invasive form of bariatric surgery isAdjustable Gastric Banding. Through this procedure the surgeon places aband around an upper part of the stomach to divide the stomach into twoparts, including a small pouch in the upper part of the stomach. Thesmall upper stomach pouch can only hold a small amount of food . Theremainder of the stomach lies below the band. The two parts areconnected by means of a small opening called a stoma. Risks associatedwith Gastric Banding are significantly less than other forms ofbariatric surgery, since this surgery does not involve opening of thegastric cavity. There is no cutting, stapling or bypassing.

It has been found that the volume of the small upper stomach pouch abovethe band increases in size up to ten times after operation. Therefore,the pouch volume during surgery needs to be very small, approximately 7ml. To enable the patient to feed the stomach with sufficient nutritionimmediately after an operation considering such a small gastric pouch,the stoma initially needs to be relatively large and later needs to besubstantially reduced, as the pouch volume increases To be able toachieve a significant range of adjustment of the band, the cavity in theband has to be relatively large and is defined by a thin flexible wall,normally made of silicone material. Furthermore, the size of the stomaopening has to be gradually reduced during the first year after surgeryas the gastric pouch increases in size. Reduction of the stoma openingis commonly achieved by adding liquid to the cavity of the band via aninjection port to expand the band radially inwardly

A great disadvantage of repeatedly injecting liquid via the injectionport is the increased risk of the patient getting an infection in thebody area surrounding the injection port. If such an infection occurs,the injection port has to be surgically removed from the patient.Moreover, such an infection might be spread along the tubeinterconnecting the injection port and the band to the stomach, causingeven more serious complications. Thus, the stomach might be infectedwhere it is in contact with the band, which might result in the bandmigrating (eroding) through the wall of the stomach. Also, it isuncomfortable for the patient when the necessary, often many,post-operation adjustments of the stoma opening are carried out using arelatively large injection needle penetrating the skin of the patientinto the injection port.

It may happen that the patient swallows pieces of food too large to passthrough the restricted stoma opening. If that occurs the patient has tovisit a doctor who can remove the food pieces, if the band design sopermits, by withdrawing some liquid from the band to enlarge the stomaopening to allow the food pieces to pass the stoma. The doctor then hasto add liquid to the band in order to regain the restricted stomaopening. Again, these measures require the use of an injection needlepenetrating the skin of the patient, which is painful and uncomfortablefor the patient, and can sometimes be the cause of infection, thusrisking the long-term viability of the implant. The adjustment of theband can be inconsistent. For example, if some air is inadvertentlyinjected with the liquid (sterile saline), it can cause somecompressibility to the pressurization media and take away some of the“one-to-one” feel when pressurizing and depressurizing.

The LAP-BAND Adjustable Gastric Banding System (Inamed) is a productused in the Adjustable Gastric Banding procedure. The LAP-BAND systemincludes a silicone band, which is essentially an annular-shapedballoon. The surgeon places the silicone band around the upper part ofthe stomach. The LAP-BAND system further includes a port that is placedunder the skin, and tubing that provides fluid communication between theport and the band A physician can inflate the band by injecting a fluid(such as saline) into the band through the port. As the band inflates,the size of the stoma shrinks, thus further limiting the rate at whichfood can pass from the upper stomach pouch to the lower part of thestomach. The physician can also deflate the band, and thereby increasethe size of the stoma, by withdrawing the fluid from the band throughthe port. The physician inflates and deflates the band by piercing theport, through the skin, with a long, non-coring needle. There is oftenambiguous feedback to the physician between the amount injected and therestriction the patient feels during the adjustment procedure, such aswhen swallowing a bolus of liquid to test the stoma. In addition, achange of as little as 0.5 ml or less can sometimes make a differencebetween too much restriction and the correct amount of restriction.

The lower esophageal sphincter (LES) is a ring of increased thickness inthe circular, smooth muscle layer of the esophagus. At rest, the loweresophageal sphincter maintains a highpressure zone between 15 and 30millimeters (mm) Hg above intragastric pressures. The lower esophagealsphincter relaxes before the esophagus contracts, and allows food topass through to the stomach After food passes into the stomach, thesphincter constricts to prevent the contents from regurgitating into theesophagus. The resting tone of the LES is maintained by myogenic(muscular) and neurogenic (nerve) mechanisms. The release ofacetylcholine by nerves maintains or increases lower esophagealsphincter tone. It is also affected by different reflex mechanisms,physiological alterations, and ingested substances. The release ofnitric oxide by nerves relaxes the lower esophageal sphincter inresponse to swallowing, although transient lower esophageal sphincterrelaxations may also manifest independently of swallowing. Thisrelaxation is often associated with transient gastroesophageal reflux innormal people.

Gastroesophageal reflux disease, commonly known as GERD, results fromincompetence of the lower esophageal sphincter, located just above thestomach in the lower part of the esophagus Acidic stomach fluids mayflow retrograde across the incompetent lower esophageal sphincter intothe esophagus. The esophagus, unlike the stomach, is not capable ofhandling highly acidic contents so the condition results in the symptomsof heartburn, chest pain, cough, difficulty swallowing, orregurgitation. These episodes can ultimately lead to injury of theesophagus, oral cavity, the trachea, and other pulmonary structures.

Evidence indicates that up to 36% of otherwise healthy Americans sufferfrom heartburn at least once a month, and that 7% experience heartburnas often as once a day. It has been estimated that approximately 1-2% ofthe adult population suffers from GERD, based on objective measures suchas endoscopic or histological examinations The incidence of GERDincreases markedly after the age of 40, and it is not uncommon forpatients experiencing symptoms to wait years before seeking medicaltreatment, even though mild cases can be successfully treated withlifestyle modifications and pharmaceutical therapy. For patients who areresistant, or refractory, to pharmaceutical therapy or lifestylechanges, surgical repair of the lower esophageal sphincter is an option.

The most common surgical repair, called fundoplication surgery,generally involves manipulating the diaphragm, wrapping the upperportion of the stomach, the fundus, around the lower esophagealsphincter, thus tightening the sphincter, and reducing the circumferenceof the sphincter so as to eliminate the incompetence. The hiatus oropening in the diaphragm is reduced in size and secured with 2 to 3sutures to prevent the fundoplication from migrating into the chestcavity. The repair can be attempted through open surgery, laparoscopicsurgery, or an endoscopic, or endoluminal, approach by way of the throatand the esophagus. The open surgical repair procedure, most commonly aNissen fundoplication, is effective but entails a substantial insult tothe abdominal tissues, a risk of anesthesia-related iatrogenic injury, a7 to 10 day hospital stay, and a 6 to 12 week recovery time, at home.The open surgical procedure is performed through a large incision in themiddle of the abdomen, extending from just below the ribs to theumbilicus (belly button)

Endoscopic techniques for the treatment of GERD have been developedLaparoscopic repair of GERD has the promise of a high success rate,currently 90% or greater, and a relatively short recovery period due tominimal tissue trauma Laparoscopic Nissen fundoplication procedures havereduced the hospital stay to an average of 3 days with a 3-week recoveryperiod at home.

Another type of laparoscopic procedure involves the application ofradio-frequency waves to the lower part of the esophagus just above thesphincter. The waves cause damage to the tissue beneath the esophageallining and a scar (fibrosis) forms. The scar shrinks and pulls on thesurrounding tissue, thereby tightening the sphincter and the area aboveit. These radio-frequency waves can also be used to create a controlledneurogenic defect, which may negate inappropriate relaxation of the LES.

A third type of endoscopic treatment involves the injection of materialor devices into the esophageal wall in the area of the lower esophagealsphincter. This increases the pressure in the lower esophageal sphincterand prevents reflux.

One laparoscopic technique that appears to show promise for GERD therapyinvolves approaching the esophageal sphincter from the outside, usinglaparoscopic surgical techniques, and performing a circumferencereducing tightening of the sphincter by placement of an adjustable bandsuch that it surrounds the sphincter. However, this procedure stillrequires surgery, which is more invasive than if an endogastrictransluminal procedure were performed through the lumen of the esophagusor stomach, such as via the mouth. Furthermore, the necessity to providefor future adjustment in the band also requires some surgical access andthis adjustment would be more easily made via a transluminal approach.

For both treatment of obesity and GERD, gastric banding has proven to bea desirable treatment option. However, despite the advantages providedby gastric banding methods, they nonetheless suffer from drawbacks thatlimit the realization of the full potential of this therapeuticapproach. For example, slippage may occur if a gastric band is adjustedtoo tight, or too loose, depending on the situation and the type ofslippage. Slippage can also occur in response to vomiting, as occurswhen a patient eats more food that can be comfortably accommodated inthe upper pouch. During slippage, the size of the upper pouch may grow,causing the patient to be able to consume a larger amount of food beforefeeling full, thus lowering the effectiveness of the gastric band. Onthe other hand, erosion may occur if the gastric band is adjusted orsecured too tightly. In either case detecting slippage or reducing therisk of erosion may be accomplished by adjusting the device to provide aproper flow rate.

Furthermore, current methods of adjusting gastric bands and restrictiondevices require invasive procedures. For example, one method requirespenetration of the abdomen with a needle in order to withdraw or injecta solution from a subcutaneous access port that is connected to a tubethat in turn regulates the inflation of the gastric band. Infection andpatient discomfort and pain are related to the use of the needlerequired to fill the gastric band with saline As a result,non-invasively adjustable gastric bands have been proposed, some ofwhich seek to provide a correct reading of the inner diameter of thegastric band at all times. However, because the wall thickness of thestomach is not uniform from patient to patient, the actual innerdiameter of the stomach at the stoma opening will be unknown. Thus, thesize of the opening of the band is at best an approximation of thestomal opening that connects the smaller upper pouch and the remainderof the stomach.

As a result, in order to properly adjust a gastric band some method ofmeasuring flow through the device or otherwise related the luminalaperture of the alimentary canal at the side of the band is needed.Current methods typically make use of radiological procedures such asX-ray fluoroscopy of barium sulfate suspensions However, the use ofX-ray procedures in a significant number of patients is highlyundesirable. The majority of gastric banding patients undergoing therapyto treat obesity are women of child-bearing age. The first few weeks ofpregnancy, when a mother may be unaware she is pregnant, is anespecially critical time of fetal development, and exposure to X-rays isto be avoided if at all possible. In addition, while fluoroscopy canmonitor flow of a radio-opaque material such as barium sulfate, it isnot particularly well suited to provide accurate information about thesize of the band aperture, the size of the lumen in the alimentary canalwhere the band is placed, or whether the band is causing secondaryproblems such as erosion of the gastric wall. Thus, it would bedesirable to have a gastric banding system that included a non-invasivemeans of adjusting and monitoring band function in the patient thatimproves on the prior art methods.

SUMMARY

In a first embodiment of the invention, a system includes an adjustableimplant configured for implantation internally within a subject, theadjustable implant having a permanent magnet configured for rotationabout an axis of rotation, the permanent magnet operatively coupled to adrive transmission configured to alter a dimension of the adjustableimplant. The system includes an external adjustment device configuredfor placement on or adjacent to the skin of the subject comprising atleast one magnet configured for rotation, the external adjustment devicefurther comprising a motor configured to rotate the at least one magnetand an encoder, whereby rotation of the at least one magnet of theexternal adjustment device effectuates rotational movement of thepermanent magnet of the adjustable implant and alters the dimension ofthe adjustable implant. The system further includes drive controlcircuitry configured to receive an input signal from the encoder.

In another embodiment, a method of adjusting an implant deviceconfigured for implantation internally within a subject is provided. Theimplant device includes a permanent magnet configured for rotation aboutan axis of rotation, the permanent magnet operatively coupled to a drivetransmission configured to alter a dimension of the adjustable implant.The method includes inputting drive instructions into drive controlcircuitry of a programmable external adjustment device comprising amotor and at least one permanent magnet configured for rotationalmovement in response to actuation of the motor. The implant device isadjusted in accordance with the instructions stored in the drive controlcircuitry of the external adjustment device, wherein the drive controlcircuitry is configured to receive an input signal from an encoder thatmeasures the angular position of one of the at least one permanentmagnet of the external adjustment device or the permanent magnet of theimplant device and terminates operation of the motor based at least inpart on the input signal from the encoder.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a patient’s torso showing the locations for placementof trocars and various other tools during a laparoscopic procedure forimplantation of an obesity control system.

FIG. 2 illustrates a side view of a trocar with an obturator removed.

FIG. 3 illustrates a side view of a trocar with an obturator in place

FIG. 4 illustrates an inflatable laparoscopic obesity control systemaccording to the prior art.

FIG. 5 illustrates a prior art laparoscopic obesity control system afterbeing locked around the stomach.

FIG. 6 illustrates a prior art laparoscopic obesity control system afterbeing secured by suturing the stomach around a portion of the inflatablering.

FIG. 7 illustrates the inflatable ring of a prior art inflatable obesitycontrol system in a non-pressurized state.

FIG. 8 illustrates the inflatable ring of a prior art inflatable obesitycontrol system with an additional 2 ml injected.

FIG. 9 illustrates the inflatable ring of a prior art inflatable obesitycontrol system with an additional 4 ml injected.

FIG. 10 illustrates an implantable obesity control system in accordancewith one embodiment.

FIG. 11 illustrates a distal section of the obesity control system in astraightened configuration (solid lines), for example, for placementinto the abdominal cavity.

FIG. 12 illustrates a restriction device of the obesity control systemjust prior to being attached.

FIG. 13 illustrates the restriction device after being attached.

FIG. 14 illustrates the restriction device after being trimmed of itsattachment leash.

FIG. 15 illustrates an alternative embodiment of a restriction device.

FIG. 16 illustrates a cross-sectional view of the outer shell or housingof the restriction device of FIG. 15 .

FIG. 17 illustrates another cross-sectional view of the outer shell orhousing of the restriction device of FIG. 15 .

FIG. 18 illustrates a cross-sectional view of the restriction devicetaken through line 18-18′ ofFIG 15.

FIG. 19 illustrates a detailed perspective view of the restrictiondevice of FIG. 15 .

FIG. 20 illustrates a perspective view of an implantable obesity controlsystem according to one embodiment.

FIG. 21 illustrates a perspective view of an external device for usewith the implantable obesity control system of the type illustrated inFIG. 20 according to another embodiment.

FIG. 22 illustrates a perspective view of the external device of FIG. 21together with the implantable obesity control system of FIG. 20

FIG. 23 illustrates a plan view of the restriction device portion of theimplantable obesity control system of the type illustrated FIG. 20 .

FIG. 24 illustrates a cross-sectional view of the restriction deviceportion of the implantable obesity control system illustrated in FIG. 23.

FIG. 25 illustrates a perspective view of an inner section of therestriction device portion of the implantable obesity control system ofFIG. 20 according to one embodiment.

FIG. 26 illustrates a perspective view of the drive shaft portion of theimplantable obesity control system of FIG. 20 . Portions of the exterioror outer windings making up the complete drive shaft have been removedfor clarity purposes.

FIG. 27 illustrates a perspective view of a sheath portion of theimplantable obesity control system of FIG. 20 .

FIG. 28 illustrates a perspective view of the drive shaft portion whichconnects to the implantable interface of the implantable obesity controlsystem of FIG. 20 according to one embodiment.

FIG. 29 illustrates a perspective view of the attachment portion of theimplantable interface of the implantable obesity control system of FIG.20 according to one embodiment.

FIG. 30 illustrates a perspective top view of the implantable interfaceportion of the implantable obesity control system of FIG. 20 .

FIG. 31 illustrates a perspective bottom view of the implantableinterface portion of the implantable obesity control system of FIG. 20 .

FIG. 32 illustrates a top down plan view of the implantable interfaceportion of FIGS. 30 and 31 .

FIG. 33 illustrates a perspective view of an RFID chip disposed near oradjacent to an implantable interface portion of an implantable obesitycontrol system of the type illustrated in FIG. 20

FIG. 34 illustrates an implantable interface according to one embodimentwhich utilizes cylindrical magnets.

FIG. 35 illustrates the implantable interface of FIG. 34 after havingbeen rotationally adjusted for custom fit in the patient.

FIG. 36 illustrates the implantable interface of FIGS. 34 and 35 with aportion removed in order to show the orientation of the poles on one ofthe cylindrical-shaped magnets.

FIG. 37A illustrates the internal drive mechanism of the implantableinterface of FIGS. 34-36

FIG. 37B illustrates the implantable interface implanted within apatient while being adjusted by an external device.

FIG. 38 illustrates the implantable interface situated adjacent or nearan external device. FIG. 38 thus represents the relative locationbetween the implantable interface and the external device after theimplantable interface has been implanted in a patient.

FIG. 39 illustrates a detailed view of the cylinder/magnet assembly ofthe external device and the implantable interface. The external deviceis shown oriented at an angle with respect to the implantable interface

FIG. 40 illustrates an alternative embodiment of the implantableinterface utilizing only one cylindrical magnet.

FIG. 41 illustrates an implantable interface secured to the fascia of apatient.

FIG. 42 illustrates an alternative embodiment of the restriction devicehaving a sliding portion.

FIG. 43 illustrates an alternative embodiment of an implantableinterface for magnetic coupling.

FIG. 44 illustrates a top view of the implantable interface of FIG. 43 .

FIG. 45 illustrates a cross-sectional view of FIG. 43 taken along line45-45′, with the implantable interface sutured to the fascia and afterseveral weeks of implantation.

FIG. 46 illustrates a perspective view of an external driver accordingto one embodiment.

FIG. 47 illustrates one alternative embodiment of an implantableinterface.

FIG. 48 illustrates the implantable interface of FIG. 47 prior toengagement or deployment of the rotatable coils.

FIG. 49 illustrates an alternative embodiment of an implantableinterface after engagement of the rotatable coils.

FIG. 50 illustrates various internal parts (without the housing) of analternative embodiment of an implantable interface which uses resonanceto turn or rotate a drive shaft.

FIG. 51 illustrates a system for driving an internally located drivenmagnet via an external device using a feedback mechanism.

FIG. 52 illustrates a plan view of an alternative embodiment of agastric restriction device.

FIG. 53 illustrates a perspective view of an alternative embodiment of agastric restriction device illustrated in FIG. 52 .

FIG. 54 illustrates a perspective view of one end of an un-latchedgastric restriction device.

FIG. 55 illustrates a detailed perspective view of a latching mechanismused for a gastric restriction device according to one embodiment.

FIG. 56 illustrates a cross-sectional view of a gastric restrictiondevice according to one embodiment.

FIG. 57 illustrates a gastric restriction device with a portion removedto show detail of the actuating elements.

FIG. 58 illustrates a perspective view of a latching mechanism for thegastric restriction device according to one embodiment.

FIG. 59 illustrates another perspective view of the latching mechanismof FIG. 58

FIG. 60 illustrates another perspective view of the latching mechanismof FIG. 58

FIG. 61 illustrates another perspective view of the latching mechanismof FIG. 58

FIG. 62 illustrates another perspective view of the latching mechanismof FIG. 58 .

FIG. 63 illustrates a magnetic slip clutch for use with an implantableinterface according to one embodiment.

FIG. 64 illustrates a perspective view of an implantable obesity controlsystem according to another embodiment.

FIG. 65 illustrates a cross-sectional view of the distal end portion ofthe obesity control system illustrated in FIG. 64 .

FIG. 66 is a plan view illustrating a connector used to connect orcouple two ends or portions of a restriction device according to oneembodiment.

FIG. 67 illustrates a perspective cross-sectional view of the housingportion of the drive transmission and proximal/distal coversencapsulating or sealing the same according to one embodiment.

FIG. 68 illustrates a cross-sectional view of the implantable interfaceaccording to another embodiment.

FIG. 69 illustrates a perspective view of a distal end of a drive cableaccording to one embodiment.

FIG. 70 illustrates a perspective view of an implantable obesity controlsystem according to another embodiment.

FIG. 71 illustrates a cross-sectional view of a proximal portion of theimplantable obesity control system of FIG. 70

FIG. 72 illustrates a perspective view of an external magnetic driveraccording to one embodiment. The outer housing or cover is removed toillustrate the various aspects of the external magnetic driver.

FIG. 73 illustrates a side or end view of the external magnetic driverof FIG. 72 .

FIG. 74 illustrates a perspective view of an external magnetic driver ofFIG. 72 with the outer housing or cover in place

FIG. 75A illustrates a cross-sectional representation of the externalmagnetic driver being positioned on a patient’s skin. FIG. 75Aillustrates the permanent magnet of the implantable interface in the 0°position.

FIG. 75B illustrates a cross-sectional representation of the externalmagnetic driver being positioned on a patient’s skin. FIG. 75Billustrates the permanent magnet of the implantable interface in the 90°position

FIG. 75C illustrates a cross-sectional representation of the externalmagnetic driver being positioned on a patient’s skin. FIG. 75Cillustrates the permanent magnet of the implantable interface in the180° position.

FIG. 75D illustrates a cross-sectional representation of the externalmagnetic driver being positioned on a patient’s skin. FIG. 75Dillustrates the permanent magnet of the implantable interface in the270° position

FIG. 76 schematically illustrates a system for driving the externalmagnetic driver according to one embodiment.

FIG. 77 illustrates a perspective view of a mount used to secure animplantable interface to a patient according to one embodiment.

FIG. 78 illustrates a fastening tool used to secure a mount of the typeillustrated in FIG. 77 to a patient according to one embodiment.

FIG. 79A illustrates a side view of a driving element portion of afastening tool according to one embodiment.

FIG. 79B illustrates an end view of a mount being loaded into a socketpositioned in the base of the driving element The view is taken alongthe line B-B′ of FIG. 79A.

FIG. 79C an end view of the central gear and four outer gears as viewedalong the line C-C′ of FIG. 79A.

FIG. 79D illustrates a perspective view of the base portion of thedriving element portion of the fastening tool.

FIG. 79E illustrates a bottom perspective view of the driving elementportion of the fastening tool.

FIG. 80 illustrates an exploded perspective view of the distal end ofthe fastening tool according to one embodiment. The base portion isomitted for clarity purposes.

FIG. 81 illustrates a perspective view of a fastener according to oneembodiment

FIG. 82 illustrates a perspective view of a mount and associatedacoustic or sonic indicator housing that contains a magnetic ball.

FIGS. 83-90 illustrate cross-sectional views of the driven magnet alongwith the acoustic or sonic indicator housing illustrating the rotationalorientation of the magnet and the magnetic ball. Various states areillustrated as the magnet rotates in the clockwise direction.

FIGS. 91-98 illustrate cross-sectional views of the driven magnet alongwith the acoustic or sonic indicator housing illustrating the rotationalorientation of the magnet and the magnetic ball. Various states areillustrated as the magnet rotates in the counter-clockwise direction.

FIG. 99 illustrates the acoustic signal as a function of time of acoupler having an acoustic or sonic housing that contains a magneticball. Peaks are seen every K rotation of the driven magnet in thecounter-clockwise direction

FIG. 100 illustrates the acoustic signal as a function of time of acoupler having an acoustic or sonic housing that contains a magneticball. Peaks are seen every % rotation of the driven magnet in theclockwise direction.

FIG. 101 illustrates the frequency response of the coupler of the typeillustrated in FIG. 82 during counter-clockwise rotation of the drivenmagnet.

FIG. 102 illustrates the frequency response of the coupler of the typeillustrated in FIG. 82 during clockwise rotation of the driven magnet

FIGS. 103-122 illustrate sagittal (i.e., lateral) sectional views of anobese patient illustrating various embodiments of laparoscopicimplantation of an obesity control system.

DETAILED DESCRIPTION

FIG. 1 illustrates the abdomen 4 of a patient 2. The navel 6 and theribline 5 are shown for reference. In typical laparoscopic surgeries forplacement of gastric restriction systems, a 12 mm trocar (or a largertrocar) is placed at first site 8. FIGS. 2 and 3 illustrate a trocar 18of this type. This trocar 18 is placed prior to insufflation (inflationof the abdominal cavity by pressurized gas, such as carbon dioxide), sofor safety purposes, often a trocar with an optically clear tip 20 isused. A scope (such as a 5 mm laparoscope) is inserted inside the tip 20and can view the separation of tissue layers and the safe entrance intothe abdominal cavity. Alternatively, instead of using the trocar tip 20to separate the tissue, an incision can first be made in the skinfollowed by finger dissection into the abdominal cavity. The trocar 18is then placed through the tract made by the finger dissection. Afterinsertion of the trocar 18, pressurized CO₂ is injected into theabdominal cavity by attaching the pressure line to a luer 22 on thetrocar 18. The pressure is maintained whether the trocar 18 has anobturator 26 in place, as in FIG. 3 , or has no obturator 26, as in FIG.2 , by the use of a trocar valve 28 The pressure inside the abdominalcavity can be maintained even after detaching the pressure line byclosing a luer valve 24.

Once insufflation is achieved, for example at a pressure of 10 to 20 mmHg, other trocars can be placed at additional sites 10, 12, 14, 16. Thetrocars placed at sites 10, 14 and 16 are typically 5 mm trocars. Site10 is located just below xiphoid process 29 of the sternum. The 5 mmtrocar placed at site 10 is removed and replaced with a liver retractor,which allows easier access and visualization of the upper portion of thestomach, and easier dissection of the surrounding features Sites 12, 14and 16 are used for the variety of laparoscopic grasping, cutting,electrosurgical, and manipulating instruments, which are usually placedthrough the trocars, with the obturators removed. Sites 8 and 12 areoften used for placement of laparoscopes through the respective trocars,for example 10 mm or 5 mm laparoscope. A 5 mm, 10 mm, or 12 mm trocar,for example can be used in site 12, depending on the size of laparoscopedesired. Many variations of this trocar placement are commonly used.This description is only relating to one particular method.

FIG. 4 illustrates a prior art inflatable obesity control system 30.Inflatable ring 32 is closed around the upper portion of the stomach,using general techniques described in, for example, Ron et al.,Laparoscopic Adjustable Gastric Banding: Surgical Technique, Journal ofLaparoendoscopic & Advanced Surgical Techniques, Vol 13, No 4, 2003,which is incorporated by reference as if set forth fully herein. Themost common current technique is known as the pars flaccida technique,which is described in the above-noted publication The inflatable ring 32is attached to itself around the stomach using a locking mechanism 34.The orientation of the inflatable band after attachment is illustratedin FIG. 5 . The stomach 50 includes a fundus 52 and a lesser curvature54 The attached inflatable ring 32 forms a small upper pouch 48 in thestomach 50, separated by a smaller diameter stoma (not visible)underneath the attached inflatable ring 32 As shown in FIG. 6 , aportion of the wall of the upper pouch is sutured to the wall of theremainder of the stomach 50 with suture 56.

Returning to FIG. 4 , port 36 is implanted at a subcutaneous site andsutured to fascia (the sheath of tissue covering muscle) by the use ofsuture holes 40. The port 36 is attached to the inflatable ring 32 by aninflation tube 42. The inflation tube 42 provides a communication meansbetween the port 36 and the inflatable ring 32 of the gastricrestriction device. The proximal end 44 of the inflation tube 42 isforced over a metal barb (not shown) which is integral with an extension38 of the port 36. This can be a difficult and time consuming portion ofthe procedure. Subsequent to the implantation surgery, the inflatablering 32 can be inflated or deflated by the injection of sterile salinethrough the port 36 by use of a syringe attached to a non-coring needle.The needle punctures the skin and subcutaneous fat and is guided throughthe septum 46 of the port 36.

Depending on the amount of restriction of the stomach desired, theinflatable ring 32 can be adjusted so that the patient feels full aftereating a small amount of food. FIG. 7 illustrates the inflatable ring 32in its non-pressurized state. Typically, during the implantationprocedure, the inflatable obesity control system 30 is primed withenough saline to fill its dead space volume while removing the air. Itis left at ambient pressure (and not pressurized) usually for the firstseveral weeks while the patient heals and the body forms a fibrouscapsule over portions where the implanted device interfaces with thestomach. After this healing period, the inflatable obesity controlsystem 30 is filled with saline as described, causing balloon 58 todistend inward radially, creating a smaller diameter stoma. FIG. 8illustrates the inflatable obesity control system 30 inflated with anadditional 2 ml of saline (beyond the initial priming volume). FIG. 9illustrates the inflatable obesity control system 30 inflated with anadditional 4 ml of saline (beyond the initial priming volume).

FIG. 10 illustrates an implantable obesity control system 60 comprisinga restriction device 62, an implantable interface 64 and a drivetransmission 66. During an initial surgical procedure, the restrictiondevice 62 is implanted in the patient so that it creates a stoma openingand controllably restricts the size of this opening between an upperpouch and the remainder of the stomach. The restriction device 62comprises a body portion 88, a first attachment portion 68 and a secondattachment portion 70. The implantable interface 64 comprises a mainbody 72 and an extension 74 which are coupled to each other by anarticulation 76. The articulation 76 allows adjustment of an angle 86between the main body 72 and the extension 74, for optimizedimplantation within the patient’s anatomy. An exemplary angle is 45°.The drive transmission 66 has a distal end 82 and a proximal end 84. Theimplantable interface 64 can be attached, detached and reattached to thedrive transmission 66 by coupling or decoupling an implantable interfaceattachment portion 78 and a drive shaft attachment portion 80. Referringnow to FIG. 11 , when the first attachment portion 68 and the secondattachment portion 70 of the restriction device 62 are not attached toeach other, the body portion 88 can be oriented in a linear orsubstantially linear shape that may be placed into the abdominal cavitythrough the inner lumen of the trocar 18, or any other type of cannula,for example, a 12 mm or 15 mm trocar 18.

Alternatively, the restriction device 62 may be placed through the tractmade after a trocar, cannula, sheath, dilator, needle or otherpuncturing device, cutting, spreading or dissecting device is placed,then removed. For example, a 10 mm or 12 mm trocar 18. The restrictiondevice 62 may also be placed through a direct incision. For example, anincision is made through the skin, and then finger dissection is used tocreate the tract through fat, fascia, muscle and other connectivetissue. A leash 90 is adjacent the first attachment portion 68 of therestriction device 62 and can be used to aid the insertion of therestriction device 62. For example, forceps or graspers are used to gripthe restriction device 62 and insert it through the trocar 18 or thetract, for example, at first site 8. For example, 5 mm laparoscopicgraspers or Rochester-Pean forceps. The first attachment portion 68, maybe chosen as the grasping point. Alternatively, the leash 90 may bechosen as the grasping point. For example, the leash 90 may be graspedat a flattened portion 92, which conforms to the jaws of the grasper orforceps. The flattened portion 92 has ribs 94 which resist slipping ofthe grasping instrument.

After the restriction device 62 is placed into the abdominal cavity, theleash 90 is grasped. The restriction device 62 is then attached, asshown in FIGS. 12, 13 and 14 . FIG. 12 illustrates the restrictiondevice 62 prior to attachment around the stomach Leash 90 is insertedthrough a hole 96, from the internal diameter side 102 towards theexternal diameter side 104. Leash 90 includes a tapered barb 98 which islarger in diameter than the hole 96 and a spaced portion 100. Afterbeing inserted through hole, and removing slack, leash 90 is pulled, forexample with a laparoscopic grasper, while traction is applied to secondattachment portion 70, until barb 98 is forced through hole 96 Becausean elastomeric material is used to construct leash 90 and secondattachment portion 70, temporary deformation occurs, allowing the partsto lock together, and forming the restriction device 62 into a closedconfiguration, as can be seen in FIG. 13

Laparoscopic cutters are now used to trim off leash 90, close to barb98. FIG. 14 illustrates the restriction device 62 after the trimming ofleash 90. It can be seen that in the prior art obesity control systemshown in FIG. 4 , the entire length of the inflation tube 42 must beinserted into the abdominal cavity because the proximal end 44 of theinflation tube 42 needs to be located laparoscopically and then insertedthrough an opening in the locking mechanism 34 in order to lock theinflatable ring 32. In the inventive embodiment, the drive transmission66 need not be inserted completely, because the first attachment portion68 and second attachment portion 70 are all that need be manipulated inorder to lock the restriction device 62 together. Likewise, the drivetransmission proximal end 84 does not need to be located within theabdominal cavity prior to the locking step

FIG. 15 illustrates a restriction device 106 having an externalperimeter 154 and a dynamic surface 152, which is allowed to constrictvia a circumferential bellows 150. In FIG. 16 , a better view of thedynamic surface 152 is visible in the cross-section. Interspersedbetween the thin walled portion 155 are ribs 156 that extend themajority of the width. The ribs 156 serve to reduce the contact area ofa belt or band that is tightened to restrict the dynamic surface 152 toa smaller diameter, and thus to lower the tensile requirement toconstrict the restriction device 106. The ribs 156 are made from thesame material as the thin walled portion 155. The material can be afoam, for example, a polyurethane foam, which allows for compression,and also allows the inner diameter of the restriction device 106 toexpand sufficiently, in the case of high stress, for example the highstress due to vomiting Alternatively, the ribs 156 are made of a rigidmetallic or polymeric material that is attached or embedded to the thinwalled portion 155. In this manner, the diameter of the dynamic surface152 can be compressed by using only a flexible rod that is pulled intension. As the rod tightens, it creates a radial force on the ribs 156,causing a wider diameter portion to restrict. This is especiallyadvantageous because now the extension portion 157 can be of smallerdimensions, because it only needs accommodate a rod and not a wide belt.

A cross-section of the restriction device 106 showing more detail of thecircumferential bellows 150 is illustrated in FIG. 17 . It can be seenthat a bias force in the form of tension from a belt or a rod will acton the dynamic surface 152 causing it to compress the diameter. Theextra wall contained in the bellows 150 allows this to occur withoutrequiring the material to have to substantially stretch, and therefore,allows this restriction to take place with a lower tension or torquerequirement. Also shown in FIG. 17 is seam 158, which can aid in themanufacturing process. The outer shell of the restriction device 106 ismolded with this seam open, and then during manufacture, the internalworkings, such as the belt, are placed inside Finally, an outer layer,such as a silicone dip, is covered around the assembly.

Returning to FIG. 15 , a drive transmission 108 couples the restrictiondevice 106 with an implantable interface. The restriction device 106 hasa first attachment portion 110 and a second attachment portion 112 whichcan be connected together, for example, around a body lumen such as thestomach. The first attachment portion 110 and the second attachmentportion 112 may also be disconnected from each other and reconnected toeach other. During the implantation surgery, it is a benefit to be ableto easily disconnect the first attachment portion 110 and the secondattachment portion 112, for example, in the case of mis-positioning. Itis also desirable to be able to easily disconnect the first attachmentportion 110 and the second attachment portion 112 at a later period oftime, for example in the case of a restriction device that requiresemergent removal, for example, due to slippage, erosion or otherreasons. The reversible attachment mechanism comprises a leash 114having a flattened portion 116 which can be easily gripped bylaparoscopic instruments, such as a grasper. Ribs 118 aid in engaging agrasper jaw that has teeth

Following the pars flaccida technique described in the Ren et al.publication, a grasper is placed through the tunnel. The grasper is usedto grasp gripping surface 120 which may also include ribs 122 for toothengagement. The first attachment portion 110 is then pulled through thetunnel by the grasper, allowing the restriction device 106 to encirclethe stomach or the area at the junction of the esophagus and stomach.The grasper is now used to stabilize the first attachment portion, bymeans of either an external gripping surface 128 (both sides of therestriction device 106), an extended gripping surface 130, or anindented gripping surface 132. While stabilizing the restriction device106 using one of these gripping methods, another grasper is used tograsp the leash 114, for example at the flattened portion 116. The tip134 of the leash 114 is inserted through an entry hole 124 until the tip134 exits through an exit hole 126. As can be seen in FIG. 18 and FIG.19 , the leash 114 comprises a male snap 142, which is configured tolock into a female snap 144 inside the first attachment portion 110 Thegrasper that was used to insert the leash 114 through the firstattachment portion 110 is now used to pull the leash 114 out the exithole 126, and pull it taut until internally, and the male snap 142 isforced into the female snap 144. A base portion 146 of the leash 114 isable to elastomerically stretch to allow this locking to take place, butalso to assure that a first face 138 presses up tightly against a secondface 140.

It should be noted that the elastomeric property of the base portion146, also allows a certain amount of compliance to the restrictiondevice 106, which, for example, allows the restricted diameter of therestriction device 106 to temporarily open up during high stress events,such as vomiting, thus protecting the stomach from slippage or erosionIf the position of the restriction device 106 is considered acceptable,the tip 134 of the leash 114 is inserted by the grasper into a slackinsertion hole 148, so that the slack of the leash is stored out of theway. If it is desired for any reason to disconnect the first attachmentportion 110 from the second attachment portion 112, the grasper is usedto grasp the leash 114 at the exit hole 126, where it remainsaccessible. By pulling to the side with the grasper, the leash 114 canbe decoupled from the first attachment portion 310 by pulling it out ofa split region 136. Split region 136 can be inherent, or it canalternatively be peel-away. Because the relevant portions of the firstattachment portion 110 are desirably made from elastomeric materials,there is sufficient compliance to allow multiple disconnections andreconnections. Alternative to the method of connecting the restrictiondevice and placing the slack of the leash 114 into the slack insertionhole 148, instead, laparoscopic cutters can be used to cut the slackportion of the leash 114. For example, by cutting the leash 114 at theexit hole 126 and removing the excess portion with laparoscopic graspers

FIG. 20 illustrates an implantable obesity control system 160 inaccordance with an embodiment of the present invention. The implantableobesity control system 160 comprises a restriction device 162, animplantable interface 164 and a drive transmission 166. During aninitial surgical procedure, the restriction device 162 is implanted inthe patient so that it creates a stoma and controllably restricts thesize of an opening between the stoma and the remainder of the stomachFor example, the restriction device 162 is laparoscopically placed intothe abdominal cavity and configured in a position surrounding thestomach. The restriction device 162 is placed through a trocar, oralternatively is placed though the opening created after a trocar isinserted and then removed. The restriction device 162 may be implantedin a patient such that a contact surface of the restriction device 162at least partially engages a surface of the gastrointestinal tract, suchas the stomach and/or the esophagus of the patient. For example, therestriction device 162 may contact, touch, attach to, affix to, fastento, access, penetrate (partially or completely) or otherwise engage thesurface of the stomach and/or the esophagus.

During this initial procedure, the implantable interface 164 is placedsubcutaneously at a site that may be subsequently accessed using anexternal device (168 in FIG. 21 ) but that does not interfere with thepatient’s mobility. Some example sites that may be used include belowthe collar bone, above the navel, and below the ribs.

FIGS. 21 and 22 illustrate an external device 168 for use with theimplantable obesity control system 160 of FIG. 20 in accordance with anembodiment of the present invention. During a follow-up procedure, therestriction device 162 may be adjusted using the external device 168without the need for penetrating the skin or entering any of the body’snatural orifices. The external device interface 169 of the externaldevice 168 is first placed adjacent the implantable interface 164, andthe restriction device 162 may then be adjusted via the interaction ofthe external device interface 169 with the implantable interface 164 toits desired size or configuration (e.g, FIG. 22 ). In certainembodiments, the external device interface 169 may be manipulated byrotation about an axis using a motor device. In certain embodiments, theexternal device interface 169 may be manually rotated about an axis inorder to adjust the size or configuration of the restriction device 162.Although in certain embodiments the restriction device 162 may be usedto restrict the esophagus or stomach for the treatment of obesity, inother embodiments the device 162 can be used for other restrictionapplications, such as gastro-esophageal reflux disease (GERD),artificial sphineters (eg., anus or urethra), annuloplasty, and full orpartial occlusion of blood vessels, such as the pulmonary artery, orblood vessels supplying a cancerous area.

The external device 168 comprises the aforementioned external deviceinterface 169 which in certain embodiments has one plane of freemovement via a pivot 170. In addition, the external device 168 maycomprise a base 171 having a handle 172. In certain embodiments, theexternal device 168 may be battery operated, as illustrated in FIG. 21 ,while in certain embodiments the external device 168 may be powered fromexternal electricity and may include a power cord In certainembodiments, the external device 168 may be configured to use batteriesthat may be rechargeable. The batteries may reside within the base 171of the external device 168 and may be held in place by the battery cover173. Buttons 174 near the handle 172 are thumb operated and includegeneric symbols for ″off,″ ″clockwise rotation″ and “counter-clockwiserotation,″ or ″off,″ ″tighten,″ and ″loosen.″ A display 175 allows thephysician or health professional performing the adjustment procedure tovisualize the current size or configuration of the restriction device162. For example, the diameter, circumference, setting number (e.g., ″1″through ″10″) or cross-sectional area of the restriction device 162 maybe visualized. In addition, the display may also show patientinformation, such as procedure dates, the patient’s name, or otherstatistics.

FIG. 23 illustrates the restriction device portion of the implantableobesity control system of FIG. 20 in accordance with an embodiment ofthe present invention. The body portion 176 of the restriction device162 comprises two attachment portions 177 and 178. When the attachmentportions 177 and 178 are not attached to each other, the body portion176 may conform to a linear shape that may be placed into the abdominalcavity though the inner lumen of a cannula. For example, the restrictiondevice 162 is configured so that it will dimensionally fit through theinternal diameter of a 15 mm or 12 mm trocar 18. It is also configuredso that it will dimensionally fit through the tract made by insertionand removal of a 10 mm or 12 mm trocar 18. The restriction device 162may be placed through a tract made after a trocar, cannula, sheath,dilator, needle or other puncturing device is placed and then removed.The restriction device 162 may also be placed through a direct incision.When the body portion 176 is oriented around the stomach or esophagus,the attachment portions 177 and 178 are joined, creating a substantiallyencircling configuration Although the body forms a substantiallycircular shape when joined using both attachment portions 177 and 178,in other embodiments the body may form a shape that is substantiallyoval, square, triangular or another shape when both attachment portions177 and 178 are joined.

In certain embodiments, the body portion 176 may comprise abiocompatible material such as silicone or polyurethane In certainembodiments, the external surface of the biocompatible material can befurther altered in order to increase biocompatibility. In certainembodiments, a biocompatible material may be used to completelyencapsulate a material that is not known to be biocompatible. The bodyportion 176 may also have holes (not illustrated) configured for theattachment of sutures, so that the restriction device 162 may be securedto the body. For example, the restriction device 162 may be attached tothe stomach using sutures. Alternatively, in certain embodiments, therestriction device 162 may have grooves or hooks configured for thesecuring of suture material. This allows the restriction device 162 tobe easily secured to the stomach wall in order to prevent slippage ofthe device or prolapse of the stomach.

In certain embodiments, the attachment portions 177 and 178 may be madefrom the same material as the body portion 176. The attachment portions177 and 178 may be made from various polymeric or metallic materials Theattachment portions 177 and 178 may be laparoscopically detached, or asection of material adjacent to the attachment portions 177 and 178 maybe laparoscopically severed if removal of the restriction device 162 isever necessitated.

FIG. 24 illustrates a cross section of the restriction device portion162 of the implantable obesity control system 160 of FIG. 20 inaccordance with an embodiment of the present invention. The body portion176 comprises an outer housing 179, a central cavity 180 and an innerdistensible member 181. A dynamically adjustable band 182 residesbetween the housing 179 and the inner distensible member 181. Thedynamically adjustable band 182 comprises a secured end 183 and amovable end 184. The secured end 183 may be coupled to the body portion176 using any fastening method, including insert molding, over molding,adhesive bonding, thermal bonding, or mechanical attachment The movableend 184 is capable of moving to either increase or decrease theoperative contact length of the dynamically adjustable band 182. Thischange in the operative contact length serves to act upon the innerdistensible member 181, causing it to increase or decrease its effectiveperimeter, which allows for the dynamic adjustment of the size or shapeof the opening between the stoma and the stomach.

The inner distensible member 181 is configured to cushion the wall ofthe stomach from any high stress concentrations imposed by thedynamically adjustable band 182, as well as minimize any pinching orfolding of the stomach wall by the movement of the dynamicallyadjustable band 182. Alternatively, the central cavity 180 may bepre-inflated with an incompressible material, such as silicone oil, inorder to create further cushioning. If pre-inflated, this also createsthe desirable situation that if there were to be break in any structure,the restriction device 162 would not draw in a large amount of bodyfluid.

FIG. 25 illustrates an inner section of the restriction device portionof the implantable obesity control system of FIG. 20 in accordance withan embodiment of the present invention. The dynamically adjustable band182 can comprise a variety of materials such as stainless steel,ELGILOY, superelastic NITINOL, polyester and Nylon (for example Nylon6/6) that allow a small thickness with high tensile strength. It canalternatively be made from a metallic or high-strength KEVLAR meshmaterial encapsulated in a polymeric material. The dynamicallyadjustable band 182 is configured with grooves 185 that allow engagementby a worm gear (186 in FIG. 24 ) The worm gear 186 is housed within agear housing 187 comprising an upper housing 188 and a lower housing189.

The drive transmission 166 is configured to turn the worm gear 186 ineither rotational direction. For example, the drive transmission 166 mayturn the worm gear 186 in the clockwise direction to tighten the band182 and in the counter-clockwise direction to loosen the band 182. Thedrive transmission 166 comprises a drive shaft 190 which turns inside asheath 191.

In certain embodiments, the drive transmission 166 may be permanentlyattached to the restriction device 162 and the implantable interface164, or it may be configured attach to and detach from the restrictiondevice 162, the implantable interface 164, or both the restrictiondevice 162 and the implantable interface 164. For example, although thedrive transmission 166 may be permanently attached to the restrictiondevice 162, the drive transmission 166 may be temporarily attachable toand detachable from the implantable interface 164. In the case of amalfunctioning implantable interface 164, the implantable interface 164may be replaced, while leaving the restriction device 162 and the drivetransmission 166 in place. The new implantable interface 164 can then beattached to the drive transmission 166. The implantable interface 164may thus be replaced without the need for placement of laparoscopictrocars.

In certain other embodiments, the drive transmission 166 may beattachable to and detachable from both the restriction device 162 andthe implantable interface 164. The implantable obesity control system160 may thus use two or more drive transmissions 166 of differinglengths. The appropriate length drive transmission 166 may be chosenbased on what best fits the anatomy of the patient in addition to thechosen surgical configuration. Additionally, if a drive transmission 166fails while the implantable obesity control system 160 is in use, then areplacement drive transmission 166 may be attached laparoscopically tothe restriction device 162 and the broken drive transmission may beremoved.

FIG. 26 illustrates the drive shaft 190 portion of the implantableobesity control system 160 of FIG. 20 in accordance with an embodimentof the present invention. The drive shaft 190 comprises an inner coil192, a middle coil 193, and an outer coil 194. In certain embodiments,all three of the coils 192, 193, 194 are wound with multi-filars of wire195. The direction of winding for the outer coil 194 and the inner coil192 are the same, while the middle coil 193 is wound in the oppositedirection. This three-layer configuration allows for torque transmissionin either direction For example, when the drive shaft 190 is turned inone direction, the outer coil 194 compresses and the middle coil 193expands, causing them to support one another. When the drive shaft 190is turned in the opposite direction, the middle coil 193 compresses andthe inner coil 192 expands, causing them to support each other.

In certain embodiments, the wires 195 are made from spring tempered 304Vstainless steel of diameters ranging from 0.003″ to 0.015″, but can alsobe made from a variety of materials, including ELGILOY, NITINOL andother metals. By making the drive shaft 190 from NITINOL or othersuperelastic materials, the drive shaft can be made resistant tokinking, which may occur during the implantation procedure. In certainembodiments, the wires 195 have a diameter of for example, 0.008″. Thethree coils may be connected to each other at the ends using anyconventional joining technique, such as welding, brazing, soldering,adhesive, or epoxy. In certain other embodiments, the drive shaft 190can be made from a braid reinforced polymeric tube or rod. In yetfurther embodiments, the drive shaft 190 can be made from a multi-linktransmission shaft. In other embodiments, the drive shaft 190 may bemade from a metallic tube that has been laser machined in a way thatcreates a mechanically linked pseudo-spiral pattern. In anotherembodiment, the drive shaft 190 may simply be made from a single wire,for example a superelastic or NITINOL wire.

FIG. 27 illustrates the sheath 191 portion of the implantable obesitycontrol system 160 of FIG. 20 in accordance with an embodiment of thepresent invention. The sheath 191, which houses the drive shaft 190, maycomprise a composite configuration, including an inner layer 196,braiding 197, an intermediate layer 198 and an outer layer 199. Theinner layer 196 comprises a material with high lubricity, such as afluoropolymer. Sample fluoropolymers include polytetrafluoroethylene(PTFE) and ethylene tetrafluoroethylene (ETFE). The use of highlubricity materials may reduce friction between the stationary sheath191 and the turning drive shaft 190.

The braiding 197 supplies mechanical strength though tension,compression and/or torsion and maintains the sheath 191 in a roundcross-section as the sheath 191 is placed in a flexed configuration. Thebraiding material may comprise 304 stainless steel, ELGILOY, MP35N,L-605 or a high strength polymeric material such as KEVLAR.Alternatively, the braiding 197 can be replaced by a metallic coil madefrom any of the aforementioned materials. For example, a NITINOL coilwhich serves to resist kinking of the sheath.

The intermediate layer 198 comprises a material that encapsulates thebraiding 197 and gives mechanical characteristics to the sheath 191,such as stiffness or torsional rigidity. For example, the intermediatelayer 198 may be of a low enough rigidity that the sheath 191 is able tocurve and comfortably fit within the patient, but of a high enoughrigidity that the sheath 191 is not able to bend into a small bendradius that would cause failure of the drive shaft 190. The intermediatelayer 198 may also comprise a material that allows adherence between theinner layer 196 and the outer layer 199 The outer layer 199 comprises abiocompatible material such as silicone, polyurethane or ETFE.

FIG. 28 illustrates the drive shaft 190 portion which connects to theattachment portion (209 in FIG. 29 ) of the implantable interface 164 ofthe implantable obesity control system 160 of FIG. 20 in accordance withan embodiment of the present invention. FIG. 29 illustrates theattachment portion 207 of the implantable interface 164 of theimplantable obesity control system 160 of FIG. 20 in accordance with anembodiment of the present invention.

In embodiments of the system 160 with an attachable/detachableimplantable interface 164 configuration, the end of the drive shaft 190includes a keyed element 200 including a raised portion 201 and anundercut portion 202. The keyed element 200 may also include a firstlead in 203 and a second lead in 204 The end of the sheath 191 includesa barb 206 The attachment portion 207 of the implantable interface 164as shown in FIG. 29 comprises a keyhole 208 and a dynamic snap 209. Thedynamic snap 209 has an interior ramp 210, a mechanical detent 211 andrelieved area 212 having a reverse ramp 213. The implantable interface164 may also contain an elastic orifice (214 in FIG. 30 ).

During attachment, the first lead in 203 is guided through the interiorramp 210 and the raised portion 201 is forced through the dynamic snap209, flexing it outward until the raised portion 201 reaches therelieved area 212. Also, during attachment, the keyed element 200engages in the keyhole 208 This attachment allows for axial securementand rotational communication between the implantable interface and thedrive shaft. Similarly, during attachment, the barb 206 engages with theinternal diameter of the elastic orifice 214 to create a hermetic sealto protect the inner workings of the connection from the body fluids.During detachment, the keyed element 200 is removed from the keyhole208, as the second lead in 204 of the raised portion 201 is guidedthrough the reverse ramp 213 and the interior ramp 210. The elasticorifice 214 is also pulled off of the barb 206 during this detachmentprocess. In certain embodiments, the attachment and detachment can bothbe performed using laparoscopic grasping and manipulating tools becauseof the attachable/detachable configuration between the drivetransmission 166 and the restriction device 162 in certain embodiments,either the second lead in 204 or the reverse ramp 213 (or both) may beeliminated from the design if a permanent attachment is desired.

FIG. 30 illustrates a front view of the implantable interface 164portion of the implantable obesity control system 160 of FIG. 20 inaccordance with an embodiment of the present invention. The implantableinterface 164 comprises an interface housing 215 and a rotatable frame216. The interface housing 215 includes suture tabs 223 for securing theimplantable interface 164 to a patient. For example, the suture tabs 223may be used to secure the implantable interface 164 to fascia coveringmuscular layers beneath the skin and fat of a patient.

The rotatable frame 216 contains several permanent magnets 217. Thepermanent magnets 217 are configured to magnetically engage acomplimentary configuration on the external device interface 169 of theexternal device 168 of FIGS. 21 and 22 above. The permanent magnets 217of the implantable interface 164 and the external device 168 areconfigured to create the maximum attraction to each other while alsoinhibiting the rotational slippage between the rotating portions of eachcomponent. This is achieved by using permanent magnets 217 which areshaped as wedges or sectors, and are oriented so that each consecutivepermanent magnet 217 faces an opposite direction. For example, in oneembodiment, the magnets 217 may be arranged in a north-south-north-southalternating configuration The sector shape makes the best use of aminimum amount of space in the assembly. The rotatable frame 216 holdsthe permanent magnets 217 securely, even though many strong attractiveand repulsive forces exist between each of the permanent magnets 217 ofa single assembly. In certain embodiments, the magnet material comprisesrare earth magnet materials, such as Neodymium-Iron-Boron (Nd—Fe—B),which have exceptionally high coercive strengths. In certainembodiments, the individual Nd—Fe—B magnets are enclosed within astainless steel casing or various layers of nickel, gold or copperplating to protect the corrosive Nd—Fe—B material from the environmentinside the body. In certain embodiments, other magnetic materials may beused, including SmCo5 (Samarium Cobalt) or AlNiCo (Aluminum NickelCobalt). In certain embodiments, Iron Platinum (Fe—Pt) may be used Ironplatinum magnets achieve a high level of magnetism without the risk ofcorrosion, and may possibly preclude the need to encapsulate. In certainembodiments, the permanent magnets 217 on the implantable interface maybe replaced by magnetically responsive materials such as VanadiumPermendur (also known as Hiperco).

In certain embodiments, the rotatable frame 216 of the implantableinterface 164 is caused to rotate via the rotation of the magnets on theexternal device interface 169 of the external device 168. In certainembodiments, the magnets on the external device are on a rotatable framewith the magnets themselves having a higher magnetism than those on theimplantable interface 164. For example, the magnets on the externaldevice 168 may also be permanent magnets of the same sector shape as theimplantable interface 164, but may be of a much larger thickness ordiameter. In other embodiments, the external device 168 may incorporateone or more electromagnets instead of permanent magnets It can beappreciated that the implantable device has relatively few componentsand does not include a motor or electronics, thus creating a simpler,less costly, more reliable device with a higher likelihood offunctioning many years after implantation.

FIG. 31 illustrates a rear view of the implantable interface portion 164of the implantable obesity control system 160 of FIG. 20 in accordancewith an embodiment of the present invention. The rotatable frame 216 ofthe implantable interface 164 is coupled to a first bevel gear 218 whichthen causes the rotation of a second bevel gear 219. The second bevelgear 219 is coupled to the drive shaft 190 (either permanently or by theattachable/detachable method described earlier). A gear ratio of lessthan 1:1 may be used (e.g., 1:3) in order to slow the rotation of thedrive shaft 190, and to increase the torque delivery to the worm gear186 of the restriction device 162. In order to ensure that therestriction device 162 is only adjusted when desired, the rotatableframe 216 is forced against a clutch 221 by a spring (222 in FIG. 30 ).The clutch 221 frictionally holds the rotatable frame 216 so that norotational movement can occur, for example, during patient movement orexercise. The magnetic engagement between the magnets of the externaldevice interface 169 of the external device 168 and the permanentmagnets 217 of the implantable interface 164 forces the rotatable frame216 to move axially towards the external device 168, compressing thespring 222 and releasing a clutch interface 224 of the rotatable frame216 from the clutch 221

FIG. 32 illustrates a direct front view of the implantable interface 164portion of the implantable obesity control system 160 of FIG. 20 inaccordance with an embodiment of the present invention The rotatableframe 216 has a square orifice 226 which is able to slide axially over asquare cross-section hub 225, without allowing rotation between the twoparts. Thus, when the external device 168 is in place, i.e., with theexternal device interface 169 adjacent the implantable interface 164,the rotatable frame 216 is magnetically pulled off of the clutch 221 andthus there is free rotation of the rotatable frame 216 caused by therotation of the corresponding mechanism of the external device 168. Theclutch 221 and the clutch interface 224 can be of several possibleconfigurations so that they may engage each other, concave/convex,plate, cone, toothed, etc.

FIG. 33 illustrates a radio frequency identification (RFID) chip 220near the implantable interface portion 164 of the implantable obesitycontrol system 160 of FIG. 20 in accordance with an embodiment of thepresent invention An RFID (radio frequency identification) chip 220 maybe implanted in a patient during the implantation of the implantableobesity control system 160. In certain embodiments, the RFID chip 220may be implanted subcutaneously in a known location, such as a locationnear the implantable interface 164. In other embodiments, the RFID chip220 may be located within the implantable interface 164. Upon theimplantation of the restriction device 162, the external device 168stores patient information on the RFID chip 220, including the currentsize of the restriction device 162, the amount adjusted, the serialnumber of the restriction device 162, the date of the procedure, patientname, flow rate of a test fluid through the stoma, and identification.With respect to flow rate measurements and various sensors, reference ismade to U.S. Provisional Pat. Application No. 60/880,080 filed on Jan.11, 2007 which is incorporated by reference as if set forth fullyherein. This application includes fully external sensors for detectingflow through the gastrointestinal lumen as well as sensors integral orincorporated with the gastric band for detecting flow through thegastrointestinal lumen, and other characteristics

During subsequent adjustment procedures, the external device 168 mayread the RFID chip 220 to determine information related to the patient,such as the current size of the restriction device 162. At the end ofthe adjustment procedure, the external device 168 may store updatedpatient information, including the size of the restriction device 162,to the RFID chip 220. An RFID antenna (not shown) in the external device168 may be used to power the RFID chip in order facilitate the read andwrite functions.

Several techniques may be used to determine the current size of therestriction device 162. In certain embodiments, the size may bedetermined indirectly by the number of rotations of the rotatableassembly of the external device 168. In certain embodiments, the sizemay be determined by the number of rotations of the rotatable frame 216of the implantable interface 164, by the number of rotations of any oneof the gears or shafts of the implantable interface 164, or by thenumber of rotations of the restriction device 162 itself. In certainembodiments, a feedback mechanism, such as a Hall effect device (twoadditional magnets that move axially in relation to each other as driveshaft rotates and therefore as the restriction device constricts orloosens), may be used to determine the current size of the restrictiondevice 162 In certain embodiments, an optical encoder feedback mechanismmay be used by placing an optical encoder in the gear box of either theexternal device 168, the restriction device 162 or the implantableinterface 164. A through-the-skin optical encoder is even envisionedthat shines a light through the skin and fat and counts successivepasses of a one or more reflective stripes on the rotatable frame 216 ormagnets 217. In certain embodiments, the external device may include anaudio sensor to determine the current size of the restriction device162. For example, the sensor may listen to the cycling sound of gearing,thus giving feedback information on the amount of total adjustment.

Any of the materials of the restriction device 162, the implantableinterface 164, the drive transmission 166 or even the external deviceinterface 169 of the external device 168 can be made from radiopaquematerials, so that the position, condition or alignment of thecomponents may be seen during the initial surgical procedure, or duringthe subsequent adjustment procedures. For example, portions of thedynamically adjustable band 182 may be made radiopaque to allow the useof fluoroscopy to determine the dimension of the restrictive device 162.Alternatively, two components on the drive transmission (one that isstationary and one that moves axially with rotation) may each beradiopaque so that the measurement of the distance between the twocomponents on a scaled x-ray will give the current size of therestriction device.

In the initial surgical implantation of some embodiments, one or moretrocars are placed into the abdomen of the patient. The abdominal cavityis insufflated, such as by using CO₂, thus creating a space within whichto perform the procedure. Laparoscopic dissecting tools are placedthrough trocars and under the visualization of a laparoscope tissue isdissected near the junction of the stomach and the esophagus Therestrictive device 162 is placed into the abdominal cavity. In certainembodiments, the restrictive device 162 is placed into the abdominalcavity through one of the trocars, while in certain embodiments therestrictive device 162 is placed into the abdominal cavity through atract made by inserting and removing a trocar. The restrictive device162 is laparoscopically placed around the desired section of the stomachand/or esophagus and secured The implantable interface 164 may beattached subcutaneously by suturing the interface 164 to the fascia.

In the adjustment procedure, the external device 168 is placed againstthe outer surface of the skin, with the external device interface 169placed adjacent the implantable interface 164. The external device 168is operated so as to magnetically adjust the restrictive device 162 viathe implantable interface 164.

FIG. 34 and FIG. 35 illustrate an implantable interface 248 which isconfigured to allow non-invasive adjustment of the restriction device.Externally, the implantable interface 248 comprises a housing 256 and astrain relief 254. The housing 256 is preferably made from rigid,implant-grade biocompatible materials such as PEEK, titanium orpolysulfone. The strain relief is preferably made from elastomeric,implant-grade materials such as silicone, polyurethane or asilicone-urethane copolymer, such as Elast-eon™. The housing 256 mayalso be coated with an elastomeric material such as silicone,polyurethane or a silicone-urethane copolymer. The implantable interface248 is coupled to the drive transmission 202 of the restriction device(e.g., restriction device 230 of FIG. 42 ). The drive transmission 202comprises a drive shaft 250 and a sheath 252. The housing 256 comprisesa first magnet cover 258, a second magnet cover 260 and an articulation262. The strain relief 254 is coupled to the articulation 262, allowingthe adjustment of an angle (α) for placement and securement to apatient. FIG. 35 shows the angle (α) adjusted to about 45° while FIG. 34shows the angle (α) adjusted to close to 0°. Other angles may bedesired, for example 180°. In addition, the housing 256 comprises aplurality of suture tabs 266 having suture holes 264, aiding in suturingthe implantable interface 248 to the fascia.

The implantable interface 248 is attachable to and detachable from thedrive transmission 202. allowing the restriction device 230 and thedrive transmission 202 to be inserted together into the abdomen, forexample through a trocar-made hole in the abdominal wall FIG. 36illustrates the implantable interface 248 with the first magnet cover258 removed. A cylindrical magnet 270 is secured within a turret 268which is capable of rotation. The cylindrical magnet 270 is polednorth-south across its diameter, as shown. Note, though two 180° sectorsare shown, alternative poling, such as four 90° sectors, alternatingnorth-south-north-south are conceived, for example by incorporating morethan one magnet, as are other variations of sector angle and sectornumber.

Turning to FIG. 37A, rotation is imparted to the drive shaft 250 bymeans of a gearing arrangement. First miter gear 272 is coupled to ashaft 276. Both cylindrical magnets 270 are coupled to the same shaft276. When both cylindrical magnets 270 are rotated by an external device278, external to the patient, it causes shaft 276 and first miter gear272 to turn. First miter gear 272 is rotatably engaged with second mitergear 274, which therefore is forced to turn when first miter gear 272turns in response to rotation of cylindrical magnets 270. Second mitergear 274 is coupled to drive shaft 250, and so the forced rotation ofthe second miter gear 274 causes the rotation of the drive shaft 250. Ifbevel gears are used in place of the miter gears, for example, whereinthe second (or follower) gear has a larger number of teeth than thefirst gear, then less torque is required to rotate the shaft 276, anddrive shaft 250 rotates at a slower rate.

The drive shaft 250 is capable of delivering torque. It can be made, forexample, from a triple coil configuration, wherein the inner and outercoils are would in one direction and the middle coil is wound in theopposite direction. The wires are made from 304 stainless steel orELGILOY or NITINOL or other metallic or polymeric materials.Alternatively, the drive shaft 250 can be made from a braided tubing(polymeric tubing with embedded braiding). This braiding can be 304stainless steel, ELGILOY, NITINOL, KEVLAR or other metallic or polymericmaterials. The triple coil type drive shaft and the braided tube typedrive shaft can both also be made with a core wire or rod in the center,for increased strength properties. If the designs allow for low enoughtorque of the drive shaft, the drive shaft 250 can be made of a singlewire, for example a 0.010″ to 0.030″ NITINOL wire. Using NITINOL in anyof the drive shaft configurations, especially in its superelastic state,makes for a more kink resistant drive shaft.

FIG. 37B illustrates the implantable interface 248 implanted within theabdominal wall 288 of a patient. The implantable interface 248 isimplanted beneath the skin 280 and the subcutaneous fat 282 and issecured to the fascia 284 covering the muscle 286 by suture 290 or othermeans. Within a number of weeks after implantation of the implantableinterface 248, the body forms a fibrous capsule around the implantableinterface 248 The implantable interface 248 is shown in FIG. 37B in apreferred configuration, with the strain relief 254 extending throughthe fascia 284 and muscle 286 in order to non-invasively adjust theconstriction amount of the restriction device 230, an external device278 is placed on the skin surface opposite the implantable interface248. The external device comprises an external device housing 292 havinga flattened surface 296 for placement on the skin 280.

Alternatively, the surface for placement on the skin 280 can becontoured to match that of the abdomen. The external device 278 is heldin place using a handle 294. Alternatively, the external device isclamped to the patient or held in place by means other than theattending operator’s hands. Batteries 300 power a motor 298 which isoperated via a switch 301. For example, the switch 301 has threesettings: an off setting, an operation of the motor in one rotationaldirection and an operation of the motor in the opposite rotationaldirection. The motor 298 rotates a motor pulley 302, which then drives acylinder 304 by means of a belt 308 and a cylinder pulley 306. It isconceived that other means of operation are all within the scope ofcausing rotation of the cylinder 304 Attached to the cylinder are fourdrive magnets 310, shown in FIG. 38 . The drive magnets are poled asshown (through their thickness) so that alternating north-south facesare seen as the cylinder rotates.

Beneath each drive magnet 310 is a back iron 312. In certainembodiments, the drive magnets are made from rare earth magneticmaterials, such as Neodymium-Iron-Boron (Nd—Fe—B), which haveexceptionally high coercive strengths. In certain embodiments, theNd—Fe—B magnets are enclosed within a stainless steel casing or aplating to protect the corrosive Nd—Fe—B material from the environmentinside the body. In certain embodiments, other magnetic materials may beused, including SmCo5 (Samarium Cobalt) or AlNiCo (Aluminum NickelCobalt). In certain embodiments. Iron Platinum (Fe—Pt) may be used. Ironplatinum magnets achieve a high level of magnetism without the risk ofcorrosion, and may possibly preclude the need to encapsulate. In certainembodiments, the permanent magnets used on the implantable interface maybe replaced by magnetically responsive materials such asiron-cobalt-vanadium alloy (also known as HIPERCO).

The back iron 312 is preferably made from steel (AISI 1018) and may becoated, for example with Parylene, but the back iron 312 can also bemade of stainless-steel The back iron 312 preferably measures about halfthe thickness of the drive magnet. The back iron serves to force most ofthe magnetic field in direction A, creating improved coupling with thecylindrical magnets 270 of the implantable interface 248. When theswitch 301 is operated to turn the cylinder 304, and thus drive magnets310 and back irons 312 in a first rotational direction 314, magneticcoupling causes the cylindrical magnets 270 of the implantable interface248 to turn in a second rotational direction 316. When the switch 301 isoperated to turn the cylinder 304, and thus drive magnets 310 and backirons 312 in a third rotational direction 318, the cylindrical magnets270 of the implantable interface 248 are forced to turn in a fourthrotational direction 320. It can be seen that the components in thisembodiment behave like magnetic gearing, with the drive and driven″gears″ engaged by magnetic attraction and repulsion.

The combination of the relatively large width of the drive magnets 310,and the effectiveness of back irons 312 to selectively shape themagnetic fields improves the coupling with the cylindrical magnets 270of the implantable interface 248 so that even a non-ideal orientation ofthe implantable interface 248 in relation to the flattened surface 296of the external device 278, as shown by angle β in FIG. 39 , can stillallow for acceptable coupling, and thus adjustment of the restrictiondevice 230. Likewise, length d from the end of the external device 278to the end of the implantable interface 248 can vary quite a bit whilestill allowing for good coupling. This is important, because thecontours of the human body to not always allow for perfect parallelalignment, and because the implantable interface 248 cannot be seenthrough the skin 280 and fat 282, and thus the true optimum alignmentcannot always be surmised.

An alternative embodiment is shown in FIG. 40 . In this single magnetimplantable interface 322, there is only one cylindrical magnet 270,giving the implantable interface 322 an “L” shape instead of a “T”shape. The benefit is that this configuration can be secured within theabdominal wall of the patient with a smaller “footprint”, and thus withless bother to the patient, either cosmetic or comfort related. FIG. 41demonstrates this configuration. An alternative single magnetimplantable interface 324 is illustrated in FIG. 41 in place within theabdominal wall 288. An additional feature of this alternative embodimentis a planetary gearbox 326, which can change the gear ratio to lessenthe torque requirement and/or lower the rotational speed, withoutaddition diameter to the housing.

The sheath 252 of the drive transmission 202 is preferably made with acoil reinforced configuration. For example, the inner layer ispolyethylene, polypropylene, nylon, polyurethane, PTFE, FEP, PFA, ETFEor other relatively low friction polymers. The coil is made fromstainless steel, ELGILOY, NITINOL, MP35N and serves to maintain a roundinner diameter, and keep sheath 252 from kinking. This is importantbecause the drive shaft 250 should in turn be free to rotate inside thesheath, even as sheath takes a curved configuration in the body over thelife of the implant, due to patient movement. The entire outer surfaceof the restriction device 230, drive transmission 202 and implantableinterface 248 are preferably made from implantable biocompatiblematerials, such as silicone, polyurethane or a silicone-urethanecopolymer, such as Elast-eon™. The outer surface may be made morelubricious via the embedding of Parylene.

The external device may also include a torque meter that measures thetorque during adjustment in order to determine whether the magnets areengaged, and thus is able to count rotations, and thus, the degree ofadjustment of the restriction. The external device may also useelectromagnets in order to generate the magnetic fields which willcouple with the implantable interface magnets. Alternatively, themagnets of the implantable interface 248 may also have back irons inorder to tailor the magnetic fields. The back iron may be steel(AISI1018) with Parylene coating, nickel and gold coating or othercoating to assure biocompatibility.

FIG. 42 illustrates an alternative embodiment of the restriction device230 having a sliding section. A belt 336 is attached permanently at thefirst attachment portion 338. The belt 336 has grooves 340 which areengaged by a worm 342 which is turned by a drive shaft 344, for example,a magnetically driven drive shaft. At the worm 342 turns, the grooves340 of the belt 336 are engaged by the threads of the worm 342, causingthe perimeter of the belt 336 to either increase or decrease. Thiscauses a female section 348 to slide over a male section 346 to eitherincrease or decrease the inner diameter of the restriction device 230.An advantage of this configuration is that the restriction device 230does not need to be made of compressible materials, such as foam. Inthis type of design, the emergent relief of stress, for example due toviolent vomiting, can be controlled by a semi-compliant relationshipbetween the attachment between the first attachment portion 338 and asecond attachment portion 350.

FIG. 43 illustrates an alternative embodiment of an implantableinterface 400. A drive transmission 202, comprising a drive shaft 250and a sheath 252 is couplable to the implantable interface 400. Theimplantable interface 400 comprises a housing 402 a flexible strainrelief 404 and a magnetically driven rotational assembly 406. Themagnetically driven rotational assembly 406 comprises a turret 408 andfour magnets 410. The turret 408 includes a keyed orifice 412, forexample in the shape of a hexagon, which can be engaged by acorresponding male shape, for example a hex 418 at the end of the driveshaft 250 (see FIG. 44 ). The turret 408 also serves to hold the magnets410 in their preferred configuration. Note that other numbers of magnetsmay be used, for example six instead of four. In the configurationillustrated, the magnets a poled through their thickness and oriented inan alternating manner (north-south-north-south) so that they arepresented at the top face 414 to couple with a driving magnet ormagnetic array in an external device (not pictured).

The external device couples with the magnets 410, causing the turret 408to turn, and in turn causing the drive shaft 250 to turn, thus allowingfor adjustment of the restriction device. FIG. 44 illustrates the driveshaft 250 and the sheath 252 prior to being coupled to the turret 408 ofthe implantable interface 400. The sheath 252 has wings 416 which areinserted into the flexible strain relief 404 and locked into the winglock 424 (see FIG. 45 ), while the hex 418 is inserted into the keyedorifice 412. The shape does not have to be a hexagon, and can be anykeyable or friction engageable shape. FIG. 45 illustrates across-section of the implantable interface 400 after it has been suturedinto a patient and after several weeks have passed, wherein the body hasgrown a fibrous capsule 426 around the implantable interface 400. Theimplantable interface 400 has been secured to the fascia 284 coveringthe muscle 286 by use of suture 290. The implantable interface 400 wasoriginally inserted through an incision 428 and into a tunnel 430between the skin 280 and fat 282 and the fascia 284 and muscle 286 Thesuturing is done through suture holes 422 in suture tabs 420. Ifnecessary, the implantable interface 400 may be subsequently removedfrom the drive transmission 202 and replaced by another implantableinterface of the same design or of a different design.

FIG. 46 illustrates an external device 472 for driving the implantableinterface 400 of FIGS. 43-45 . External device 472 comprises a head 474,a handle 476 and an articulation 478 that allows adjustment of the angleof the head 474 in relation to the handle 476. In use, front face 480 isplaced against skin 280, opposite implantable interface 400. Fourdriving magnets 482 are arrayed on turret 484 in staggered(north-south-north-south) orientation. The turret 484 can be rotatedwithin a housing 486 of head 474. Back iron 488 is approximately 50% ofthe thickness of each of the driving magnets 482. Back iron is a flatring disk made from steel 1018, with an inner diameter matching theinner arc and an outer diameter matching the outer arc of each of thesector shaped driving magnets 482. Switch 490 is a three position switchcontrolling the operation of a motor which is either off, rotatingclockwise or rotating counter-clockwise. The motor controls the rotationof the turret 484 The back iron 488 serves to orient the magnetic fieldsso that they are optimized in the direction of the implantable interface400, and thus maximize magnetic coupling The outer diameter of themagnet/back iron assembly is approximately 150% that of the diameter ofthe magnetically driven rotational assembly 406 of the implantableinterface 400 The larger diameter of the magnet/back iron assembly inrelation to the magnetically driven rotational assembly 406 allows forsufficient magnetic coupling, even if the external device 472 is notperfectly centered and angularly oriented in relation to the implantableinterface 400. The spacing 492 between the driving magnets 482, alsominimizes attraction between each of the adjacent magnets which may beantagonistic to the extent of coupling between the external device 472and the implantable interface 400 An exemplary spacing is 5° to 15°. Itshould be noted that at maximum torque transfer, the poles of thedriving magnets 482 are not perfectly aligned with the opposite poles ofthe magnets 410, but rather there is a nominal angular offset.

An alternative securing mechanism for an implantable interface 432 isillustrated in FIGS. 47-49 . Currently, securing implantable couplers,for example injection ports for hydraulic gastric bands, using sutureinserted through suture holes, can be time consuming and can sometimeslead to a port that is not evenly sutured at every suture location. Thiscan lead to flippage of the port. An improvement for securement of bothports for hydraulic gastric bands, ports for other purposes or for theimplantable interfaces described within the scope of this invention isillustrated in FIG. 47 . The implantable interface 432 comprises acentral portion 434, which may include a diaphragm (in the case of aninjection port) or a magnetic assembly (in the case of a magneticallydriven interface). The implantable interface 432 also comprises an outerportion 436 which includes keyholes 438 and rotatable coils 440. Therotatable coils 440 are rotated by placing a driver into one of thekeyholes 438 and turning it. The rotatable coils 440 are connected to adriven head, for example a hex head, and the driver can be a matchinghex head. For attachment to the fascia, the interface surface 442 isplaced on top of the fascia and a slight force is placed on theimplantable interface 432. A driver is placed into one of the keyholes438 and into the hex head which is attached to one of the rotatablecoils 440. The tip 444 of the rotatable coils 440 is sharp, so that iteasily imbeds in the fascia. As the rotatable coil 440 is turnedclockwise, the tip 444 embeds deeper and deeper into the fascia Allrotatable coils 440 can be secured into the fascia separately, or agearing system, such as a planetary gearing system, can be used so thatonly one keyhole 438 is necessary, and allows the tightening of allrotatable coils 440 in unison. FIG. 48 illustrates the implantableinterface 432 with the coils 440 retracted and FIG. 49 illustrates theimplantable interface 432 with the rotatable coils 440 tightened. Therotatable coils 440 may be axially free within the keyholes, so thatonly the circumferential engagement into the fascia causes them toadvance axially (like a wood screw). Alternatively, the rotatable coils440 may be within a tapped structure within the keyholes 438 so that theturning of the rotatable coils 440 by the driver causes a specific axialengagement with each turn (as the tip 444 moves circumferentially it isalso forced axially at a specific rate). If it is desired to remove theimplantable interface 432, the rotatable coils 440, can be turnedcounter-clockwise to remove them from the fascia.

Alternative improvements include the following. It may be desired thatafter securement, the rotatable coils 440 be contactable by anelectrosurgical device, in order to heat the tissue surrounding therotatable coils 440, in order to promote local scarring and better holdthe rotatable coils 440 in place. Because the securement of therotatable coils is most important in the first several weeks (forexample two weeks to six weeks), and in various applications is lessimportant after this period (when the fibrous capsule has formed overthe implantable interface 432), it is conceived that the rotatable coils440 may be detachable, for example in the cases wherein easy removal ofthe implantable interface 432 is desired. Another way of achieving thisis by making the rotatable coils 440 from a material that isbiodegradable or bioabsorbable and will disappear in a time period afterthe important several weeks. An example of such material is magnesium.

FIG. 50 illustrates an alternative embodiment to the implantableinterface using a resonance method to make the drive cable 250 rotate.In FIG. 50 , an outer housing is not shown, in order to better displaythe detail of the internal workings. The resonance mechanism 446comprises a frame 448, a circular ratchet plate 450, a first resonancebeam 452, a second resonance beam 454, a first pawl 456, a second pawl458, a first magnet 460 and a second magnet 462. The first magnet 460and the second magnet 462 are attached respectively to the firstresonance beam 452 and the second resonance beam 454. The two resonancebeams are attached to the frame 448 at one end by use of a clamp 464. Anexternal device having a rotating magnet or a pistoning magnet isoperated using a specific repeating frequency that is identical to theresonating frequency of the first resonance beam 452. For example, theexternal device, consisting of a rotating magnet, is rotated at afrequency of 100 Hz, the resonance frequency of the first resonance beam452. At this frequency, the repetitive attraction and repulsion of thefirst magnet 460 causes the first resonance beam 452 to oscillate indirection (D) at an amplitude (A). If this frequency of the rotatingmagnet is increased or decreased, the first resonance beam 452 will notoscillate at its resonant frequency, and therefore will resist thedevelopment of sufficient amplitude (A).

Likewise, because second resonance beam 454 has a resonance frequency of180 Hz, it will not sufficiently oscillate when the external magnet isrotated at 100 Hz. As the first resonance beam 452 oscillates at 100 Hzand amplitude (A), a first pawl 456 attached to the first resonance beam452 engages and moves ratchets 466 of the circular ratchet plate 450,causing the plate to turn, for example 0.010″ tangentially with eachcycle. For example, if the pawl is at a diametrical location of thecircular ratchet plate 450 that is 1″, then the disk will turn (100/sec)(0.010″)/3.14″ or about one turn every three seconds. The resonanceactivated rotation of the circular ratchet plate 450 causes gearing 468to engage and thus turns shaft 470 to which is attached drive shaft 250.If this first direction of rotation corresponds to the compression ofthe restriction device, then the relaxation of the restriction devicecan be achieved by operating the external device so that the magnetrotates at 180 Hz, which is the resonant frequency of the secondresonance beam 454. Now the second resonance beam 454 will oscillate at180 Hz at an amplitude of A′, causing a second pawl 458 to engage andmove circular ratchet plate 450 in the opposite direction, thus causingthe drive shaft 250 to turn in the opposite direction, and to relax therestriction device.

Alternatively, a single resonance beam structure, centered on the frame,can be used that allows the single beam to pivot to one side or theother of the circular ratchet plate (depending on the direction ofrotation of the external magnet). Thus, when the external magnet isrotated in a first direction, the beam pivots to one side of thecircular ratchet plate and causes the ratchet plate to turn in a seconddirection. When the external magnet is rotated in a third direction,opposite of the first direction, the beam pivots to the opposite side ofthe circular ratchet plate and causes the ratchet plate to turn in afourth direction, opposite of the second direction.

It should be noted that on all of the magnetically-aided resonance beamdesigns, the oscillation of the beam is very insensitive to the locationof the external magnet, making it easy for the attending physician ormedical personnel to perform the adjustment of the restriction device,without too much concern for finding the correct placement of theexternal device.

Instead of using implanted magnets, the implantable interface using theresonance mechanism (but no magnets) can be implanted so that it touchesa bone structure so that an external vibrator placed close to the bone(for example the rib) will cause the resonance of the beams at theselected frequencies.

FIG. 51 illustrates a system 1400 for driving an internally locateddriven magnet 1402 of an implanted device 1403 via an external device1406 using a feedback mechanism. One or more implanted driven magnets1402 are coupled magnetically through the skin 1404 of a patient 1408 toone or more external drive magnets 1410. A rotation or movement of theexternal drive magnets 1410 causes an equal rotation of the drivenmagnets 1402. Turning the driven magnets 1402 in one direction 1412causes a restriction device 1414 to close while turning the drivenmagnets 1402 in the opposite direction causes the restriction device1414 to open. Changes to the restriction device 1414 diameter aredirectly proportional to the number of turns by the one or more drivemagnets 1410.

The drive magnets 1410 are rotated by the external device 1406, whichhas an electric gear motor 1416 which is controlled by a programmablelogic controller (PLC) 1418. The PLC 1418 outputs an analog signal 1420to a motor drive circuit 1422 which is proportional to the motor speeddesired. The PLC 1418 receives an analog signal 1424 from the motordrive circuit 1422 that is proportional to the current draw of themotor. The gear motor’s 1416 current consumption is proportional to itsoutput torque. An electronic torque sensor may be used for this purpose.

The PLC 1418 receives a pulsed input signal 1426 from an encoder 1428that indicates the angular position of the drive magnet 1410. The PLC1418 controls a spring loaded braking system 1430 that automaticallystops the drive magnet 1410 if there is a loss of electrical power orother emergency

A slip clutch 1432 is included between the gear motor 1416 and the drivemagnet 1410 to prevent the gear motor 1416 from over torquing the drivenmagnet 1402 and potentially damaging the implanted device 1403.

The PLC 1418 has a built in screen 1434 to display messages and a keypad1436 for entering data. External push button switches and indicatorlights may be incorporated for user comfort and ease of use.

The motor current (output torque) is monitored continuously whenever thedevice is turning. If the motor current exceeds the maximum allowablecurrent (based on safety requirements of the device components and/orpatient tissue) the gear motor 1416 is stopped and the brake 1430 isapplied. This can be done both in software and hardware. The mechanicalslip clutch 1432 also prevents over torquing of the device. An exemplarythreshold torque is 3.0 ounce-inches.

Each patient will have a number that corresponds to the diameter oftheir restriction. A fully open device will have a number such as 2.80cm for its internal diameter and a fully closed device will have anumber such as 1.50 cm.

This number can be stored on an electronic memory card 1438 that thepatient 1408 carries. The PLC 1418 can read the current number from thememory card 1438 and update the number after adjustment. The patient’snumber can be recorded manually in the patient’s chart and kept at thephysician’s office or printed on an information card that the patientcarries. Alternatively, the information can be stored on and read froman RFID chip implanted in the patient.

The patient’s number is first entered into the PLC 1418 so it knows thepatient’s starting point. If the patient’s records are completely lost,the system can always fully open the restriction device 1414 (a knownstarting point) The number of turns to fully open the restriction device1414 can be counted and the device can then be returned to the samerestriction position.

A physician may adjust the restriction device 1414 several ways. Anabsolute move to a new restriction diameter may be entered directly. Forexample, a patient 1408 currently at 2.00 cm diameter may need to beadjusted to 1.80 cm diameter. The physician simply enters the newdiameter and presses a ‘GO’ button. The physician may prefer a relative(incremental) move from the current diameter. Each press of a buttonwill cause the device to open or close a fixed amount, say 0.20 cm ofrestriction diameter, or 0.02 cm. Finally, there may be provided openand close buttons which open/close the restriction device 1414 as longas the button is held.

Once the external device 1406 is commanded to move, the PLC 1418 slowlyramps up the speed of the gear motor 1416 while monitoring the motorcurrent (torque). A known minimum drive torque must be present forverification that the magnetic coupling to the restriction device islocked and not slipping. The minimum torque value can be a curve that isstored in the PLC 1418 that is based on the current restriction device1414 diameter, the direction of movement (opening/closing), even themodel number or serial number of the restriction device.

Also, if a sudden torque reversal is detected by the PLC 1418, a sliphas occurred As the like magnet poles (North-North & South-South) whichare repelling slip past each other, they are attracted to the adjacentopposite poles (North-South & South-North). This causes a momentaryreversal of drive torque. This torque reversal can be detected by thePLC 1418. If a slip occurs, the PLC 1418 can subtract the appropriateamount from the move. If too many consecutive slips occur, the PLC 1418can stop and display a message.

As the drive magnet 1410 rotates, revolutions and fractions ofrevolutions are counted by the PLC 1418 and converted to changes in therestriction. Once the move is complete, the PLC 1418 stops the gearmotor 1416 and applies the brake 1430

The feedback mechanism mentioned in the prior paragraphs is applicableto the external device 472 of FIG. 46 , and any other type of magneticdrive, for example an external device that drives the implantableinterface using a rotating turret containing electromagnets (instead ofthe permanent magnets presented previously).

Any of the compatible configurations of a) restriction device, b) drivetransmission c) implantable interface and d) external device areconceived to be combinable as alternative embodiments to thosepresented. In addition, the compression of the restriction device can beachieved by any of the designs and methods by using a rotating driveshaft, or by a tension/compression member. In other words, rotation canbe done only to proximal assemblies or assemblies within the implantableinterface, which then, through gearing, cause longitudinal shortening orlengthening of a wire or cable, which pulls tension on a belt or rod tocause the restriction device to compress or expand (decrease or increasein inner diameter).

FIGS. 52, 53, and 54 illustrate an alternative embodiment of arestriction device 800 having a first attachment portion 802 and asecond attachment portion 804. First attachment portion 802 comprises atab 806 having an indentation 808 and a molded end piece 810 having anend grasping fin 812. The restriction device 800 also comprises aconstrictable section 814 made up of deformable segments. Therestriction device 800 also comprises a drive extension 818 which housesthe actuating mechanism 820, seen in FIGS. 56-58 . In FIGS. 52 and 53 ,the drive transmission is not shown, but extends from end 822 of driveextension 818. End 822 of drive extension 818 comprises drive graspingfins 826. Second attachment portion 804 comprises latching mechanism824, which is described in more detail in FIGS. 58-62 .

A grasper is placed through the tunnel made in the pars flaccidaapproach and the first attachment portion 802 is grasped by tab 806, asthe first attachment portion 802 of the restriction device 800 is pulledthrough the tunnel. Alternatively, the laparoscopic grasper pulls bygrasping the end grasping fin 812. Alternatively, the laparoscopicgrasper pulls by grasping the entire thickness of the restriction device800 at the first attachment portion 802. Once the restriction device 800is straddling the tunnel, the first attachment portion 802 is grasped onthe and grasping fin 812 by the grasper (or on the entire thickness ofthe restriction device 800), and the restriction device 800 isstabilized, for example by grasping the drive extension 818 by a secondgrasper. In this procedure, each of the laparoscopic graspers may beplaced through its own 5 mm trocar. The tab 806 is then inserted intothe latching mechanism 824 of the second attachment portion 804, and thefirst attachment portion 802 and the second attachment portion 804 arelatched together. In addition, the process can be reversed in a similarmanner to unlatch.

The latching and unlatching procedure is described in reference to FIG.55 as well as FIGS. 58-62 . In order to clearly show the latchingmechanism 824, the molded end piece 810 and the rest of the firstattachment portion 802 are not shown, and are visually cut from the tab806 at line (1). Latching mechanism 824 comprises the tab 806, a slide828, a retention member 830 and a spring lock 832. To latch the firstattachment portion 802 to the second attachment portion 804, the tab 806is inserted into the retention member 830 until the indentation 808slides over the spring lock 832. FIG. 55 shows the first attachmentportion 802 and the second attachment portion 804 latched together inthis manner.

FIGS. 58-62 illustrate the various steps of latching and unlatching, andare shown with the retention member 830 removed, for purposes ofclarity. FIG. 58 shows the tab 806 as it is being inserted. FIG. 59shows the tab 806 after it has been slid past the spring lock 832. Thespring lock 832 is angled so that it easily flexes while the tab 806 isslid by it during latching. However, the spring lock 832 will not allowthe tab 806 to be unlatched as shown in FIG. 60 . The extreme edge ofthe spring lock 832 catches the edge inside the indentation 808 of thetab 806 at retention point 834. Retention member 830 (not shown in FIG.56 ) assures that the tab 806 is forced against the spring lock 832. Inorder to unlatch, the slide 828 is grasped at wall 836 betweendepression 838 and the rest of slide 828, and is forced in direction(d), as shown in FIG. 61 . Or the tip of a grasper or other surgicaltool can be placed into the depression 838 to move the slide 828 Thiscauses slide 828 to move over spring lock 832, forcing it down andcovering it. This also releases the spring lock 832, from its lockingarrangement with the tab 806. Tab 806 is now free and the firstattachment portion 802 is unlatched from second attachment portion 804.Instead of a depression 838. alternatively, the slide 828 may have a finor gripping surface.

The actuation of the restriction device 800 is shown in sectional viewin FIG. 56 and in FIG. 57 (with drive extension 818 removed forclarity). Restriction device 800 comprises a housing 842 having an outerwall 848, an inner surface 844 and an inner wall 846. A belt 840 resideswithin an internal cavity 850. The belt 840 may include the tab 806 atthe first attachment portion 802, or the tab 806 may be a separateentity. The belt 840 is coupled to a nut 852, for example, by means of acurved retaining portion 854 at the extreme end of the belt 840.Rotation of drive shaft 856 turns coupling 858 which then turns screw860. Screw 860 can be made from a number of materials, includingstainless steel, titanium, NITINOL, nylon or other metallic or polymericmaterials. An exemplary size for the screw is 0-80 UNF, though the screw860 may be larger or smaller. The nut 852 has a matching female threadand is preferably a different material than the screw 860, to reducestatic or dynamic friction. For example, nut 852 is made from bronze,acetal (Delrin), nylon, PEEK, stainless steel or other metallic orpolymeric materials.

As the screw 860 turns, the nut 852 moves axially. For example, when thedrive shaft 856 is turned clockwise (for example via magnetic couplingbetween an external device and an implantable interface), the nut 852moves in direction (a), as shown in FIG. 56 This tightens the belt 840,and thus constricts the restriction device 800. A counter-clockwiserotation of the drive shaft 856, causes the nut to move in direction(b), thus loosening the belt 840, and lessening the constriction of therestriction device 800. The screw 860 is held in tension by coupling 858and bearing 862. Bearing 862 may be, for example, a ball bearingconstructed of ceramic, glass or sapphire. The use of the fine threadedscrew 860 and nut 852 assembly to controllably apply the tension on thebelt 840 greatly reduces the amount of torque required to turn the driveshaft 856, and thus, in a magnetically driven system, minimizes therequired size of the implanted magnet

As in the ball bearing constructed of ceramic, glass, or sapphire, theother elements of the actuating mechanism 820 can be made of MRI safematerials, such as many of those mentioned. This eliminates thepossibility of movement of the restriction device 800 in the patientduring an MRI scan, or heating of the restriction device 800, orinterference or artifact on the image being created in a body area nearthe restriction device 800 The belt 840 may be made of metallicmaterials or polymeric materials. For example, PET with a thickness of0.005″to 0.015″. NITINOL, with a thickness of 0.003″to 0.007″. Nylon,with a thickness of 0.010″to 0.020″. PVC, with a thickness of 0.012″to0.024″. The belt 840 may also be made of stainless steel. Returning nowto FIG. 52 and FIG. 53 , the multiple deformable segments 816 allow fora controlled constriction of the interior of the restriction device 800as the device is constricted.

FIG. 63 illustrates a magnetic slip clutch 902 for use with animplantable interface 900 Drive shaft 904 is coupled to hub 910. Fourclutch magnets 914 are coupled to hub 910 so that hub 910, clutchmagnets 914, and drive shaft 904 rotate in unison Sheath 906 andflexible strain relief 908 are non-rotationally coupled to housing 916of implantable interface 900. Driven magnets 912 rotate together basedon magnetic coupling between the drive magnets or electromagnets of anexternal device. The only coupling between the driven magnets 912 andthe drive shaft 904 is via the magnetic coupling of each individualclutch magnet 914 to each individual driven magnet 912. Gap (g) ischosen so that at a maximum desired torque, the torque overcomes themagnetic attraction and the driven magnets 912 slip in relation to theclutch magnets. Slippage protects against over-torquing, which couldcause failure of the components of the device. For example, the driveshaft 904.

FIG. 64 illustrates an implantable obesity control system 1000 accordingto another embodiment of the invention. The implantable obesity controlsystem 1000 includes a restriction device 1002, an implantable interface1010, and a drive transmission 1020. The restriction device 1002includes an adjustable body portion 1004 that changes the size and/orshape in response to the driving action of the implantable interface1010 and coupled drive transmission 1020 (explained in detail below).The adjustable body portion 1004 may include a flexible jacket 1006 thatis shaped in an undulating or wavy-shape as illustrated in FIG. 64 . Theflexible jacket 1006 may be formed from a biocompatible polymer such as,for instance, polyurethane silicone or a silicone-urethane copolymer,such as ELAST-EON. An optional tab 1008 or the like may be secured to anexterior portion of the flexible jacket 1006 and used to hold ormanipulate the restriction device 1002 during, for instance, placementand/or adjustment of the restriction device 1002.

Still referring to FIG. 64 , the restriction device 1002 includes aconnector 1012 that is used to secure the flexible jacket 1006 in thecircular or looped configuration as illustrated in FIG. 64 . Theconnector 1012 includes a proximal portion 1014 that links the flexiblejacket 1006 to the proximal aspects of the system 1000. As used herein,the proximal direction refers to a direction or location that isdisposed toward or closer to the implantable interface 1010. Conversely,the distal direction refers to a direction or location that is disposedaway from the implantable interface 1010. The connector 1012 furtherincludes a distal portion 1016 secured to a distal end of the flexiblejacket 1006 that is configured to engage with the proximal portion 1014of the connector 1012. In one aspect, the distal portion 1016 of theconnector 1012 includes a groove or recess 1018 that is dimensioned toreceive the proximal portion 1014 of the connector 1012. Preferably, theproximal portion 1014 can be locked or fixedly secured with respect tothe distal portion 1016 through the use of one or more tabs, detents,locking members and the like (described in more detail below). In oneaspect, as described in more detail below, the proximal portion 1014 andthe distal portion 1016 of the connector 1012 may be unlocked to therebyopen the flexible jacket 1006 from the circular or looped configurationas illustrated in FIG. 64 .

Still referring to FIG. 64 , the system 1000 includes a drivetransmission 1020 that, in one aspect of the invention, is used totranslate rotational movement of a magnetic element (not shown in FIG.64 ) contained in an implantable interface 1010 into linear movement ofan actuator (not shown in FIG. 64 ) that adjusts the dimensions orconfiguration of an internal opening formed in the restriction device1002. FIG. 64 illustrates a housing portion 1022 that includes aninterior aspect that contains the mechanical transmission elements foreffectuating the translation of rotational movement into linearmovement. The housing portion 1022 is connected to a distal sheath orcover 1024. The sheath 1024 includes a lumen therein (not seen in FIG.64 ) for holding the linear driven actuator that is used to alter thedimensions and shape of the internal opening formed in the restrictiondevice 1002 The sheath 1024 may be formed from a spiral-wound wire (e.g,NITINOL) that is coated or covered on the exterior with a polymer tubeor flexible coating (e.g., polyurethane). The interior may also beoptionally coated with a lubricious polymer coating (e.g., PTFE) toreduce frictional engagement with the moving components of the drivetransmission 1020. As seen in FIG. 64 , a proximally located sheath orcover 1026 couples the housing portion 1022 to the implantable interface1010 The proximally located sheath 1026 also includes a lumen thereinconfigured for receiving a rotational drive member such as drive cableor the like. The proximally located sheath 1026 may be made of the sameconstruction as described above with respect to the distal sheath 1024.Preferably, the proximal and distal sheaths/covers 1026, 1024substantially prevent bodily fluids or the like from entering thehousing portion 1022, implantable interface 1010, and the mechanicaltransmission elements contained in the sheaths/covers 1024, 1026.

FIG. 65 illustrates a cross-sectional view of the restriction device1002 As seen in FIG. 65 , the flexible jacket 1006 contains an innerlumen or recess 1028. An actuating member 1030 is located within thislumen or recess 1028 and is fixedly secured at one end to the distalportion 1016 of the connector 1012. The actuating member 1030 mayinclude a filament, wire, tape, or other elongate structure For example,in one aspect of the invention, the actuating member 1030 may includeNITINOL wire having an outer diameter of around 0.0012 inches. Theactuating member 1030 may be secured to the distal portion 1016 of theconnector 1012 using an adhesive, crimp or friction fit, weld, oranchor. For example, in FIG. 65 , a stainless steel lug 1031 is bondedto the distal end of the NITINOL actuating member which is used toanchor the distal end of the actuating member in place.

Still referring to FIG. 65 , a series of ribs 1032 are located withinthe jacket recess 1028. The ribs 1032 are preferably spaced periodicallyabout the recess 1028 with substantially constant spacing between atleast some of the ribs 1032. In addition, the location of the ribs 1032are located in the radially inward portions of the undulating or wavyflexible jacket 1006. The ribs 1032 advantageously assist the adjustablebody 1004 to change its shape in a substantially uniform manner withoutany kinking or buckling of the material forming the flexible jacket 1006As seen in FIG. 65 , the actuating member 1030 passes over an outerportion of each rib 1032. Optionally, a groove, hole, or the likelocated in each rib 1032 (not shown) may be used to properly orient andmaintain contact between the actuating member 1030 and each rib 1032. Aspartially seen in FIG. 65 , the actuating member 1030 is secured at oneend to the distal portion 1016 of the connector 1012. The actuatingmember 1030 then passes through the flexible jacket 1006 and out theproximal portion 1014 of the connector 1012. The actuating member 1030continues onward in the proximal direction until it reaches the housing1022 (shown in FIG. 64 ). Alternatively, the actuating member 1030 maybe serially attached to an extension spring or analogous mechanism thatallows the constriction of the restriction device 1002 to open a limitedamount during an acute event, such as violent vomiting, thus serving asa safety feature to protect the tissue of the patient’s stomach oresophagus. For example, the actuating member 1030 may be attached at oneof its two ends via a spring whose spring constant is chosen to coincidewith the pressure seen during significantly violent vomiting, forexample greater than 200 mm Hg Because this pressure is higher than theupper pressure commonly seen in normal gastrointestinal tract mechanics(120 mm Hg), a mechanism of this nature will not inadvertently allowpatients to easily gorge on food The length of the spring can be chosento correspond to the total amount of diametrical relief that is desiredduring an acute violent vomiting event.

FIG. 66 illustrates a top down view of the connector 1012 with theproximal portion 1014 of the connector 1012 being in a lockedconfiguration with respect to the distal portion 1016 of the connector1012. As seen in FIG. 66 , the distal portion 1016 of the connector 1012includes a recess 1018 dimensioned to receive the proximal portion 1014of the connector 1012 The recess 1018 and/or proximal portion 1014 maybe configured in a keyed arrangement such that the proximal connectorportion 1014 may only be inserted into the distal portion 1016 of theconnector 1012 in a correct orientation. FIG. 66 , for example,illustrates a keyed portion 1034 in the form of a raised surface thatenables the correct orientation between the distal and proximalconnector portions 1014, 1016.

Still referring to FIG. 66 , the distal connector portion 1016 includesa biased locking member 1036 that is affixed at one end to a surface ofthe recess 1018 of the distal connector portion 1016. The biased lockingmember 1036 includes a free end 1038 that is used as a locking surfaceto retain the proximal and distal connector portions 1014, 1016 in alocked configuration. The biased locking member 1036 may be made of amaterial (e.g., biocompatible polymer, metal, etc.) that naturally isbiased to position the free end 1038 away from the surface of the recess1018. In order to achieve the locking arrangement, the proximalconnector portion 1014 includes an indent or groove that has anengagement surface 1040 that contacts the biased free end 1038 of thelocking member 1036. For example, if the distal connector portion 1016were moved in the direction of arrow A, the free end 1038 of the biasedlocking member 1036 would contact the engagement surface 1040 and thusprevent the unlocking of the proximal and distal connectors 1014, 1016.

Still referring to FIG. 66 , a filament 1042 is secured to the biasedlocking member and terminates outside the connector 1012 via apassageway 1044 located in the distal connector portion 1016 Thepassageway 1044 may include a hole or groove through which the filament1042 can pass. The filament 1042 may be made from, for example, suturefilament or other biocompatible material. The filament 1042 may belooped as is shown in FIG. 66 or it may have one or more strands. Anexemplary material for the filament 1042 is monofilament polypropylene

In one aspect, the filament 1042 may be made sufficiently long to passalong all or a portion of the length of the restriction device 1002,1102 to terminate at or near the implantable interface 1010, 1104. Forexample, a separate lumen (not shown) may be used to hold the filament1042 along the length of the restriction device 1002, 1102 and terminateat a location that is subcutaneous. If there is an emergency situation,the restriction device 1002, 1102 can be detached from thegastrointestinal tract (e.g., stomach) without completely removing thedevice 1002, 1102 which can be done at a later time if need be. In thisaspect of the invention, with a simple incision, the end of the filament1042 is exposed and can be pulled proximally so as to detach therestriction device 1002, 1102 from the site of interest. Once theemergency situation ends, the incision is closed with suture, and adetermination can be made later whether the entire device 1002, 102needs to be removed via surgery, or if it can later be salvaged andlaparoscopically reattached.

FIG. 67 illustrates a perspective cross-sectional view of the housingportion 1022 and proximal/distal covers 1026, 1024. The housing portion1022 includes end caps 1023A, 1023B that seal the internal portions ofthe housing from the external environment. As seen in FIG. 67 , a drivecable 1050 is located within the central lumen of the proximal sheath1026. The drive cable 1050 may be formed from, for example, the driveshaft 190 of FIG. 26 for improved torque response and kink resistance.For instance, NITINOL wire wound in a manner described in relation withFIG. 26 , with the drive cable 1050 having an outer diameter of around0.0057 inches may be used. Of course, other metallic wires such asstainless steel or ELGILOY may also be used. Still referring to FIG. 67, the drive cable 1050 is secured to a lead screw 1052 located in thehousing portion 1022 The drive cable 1050 may be secured to the leadscrew 1052 using coupler 1054 which may include a section of tubinghaving different ID for insertion of the lead screw 1052 and drive cable1050. The section of tubing 1054 may be crimped or welded to the drivecable 1050 and lead screw 1052 to fixedly secure the drive cable 1050and lead screw 1052 to one another.

Still referring to FIG. 67 , the lead screw 1052 is rotationally heldwithin the housing 1022 via two ball bearings 1056 mounted on opposingends of the housing 1022. In this regard, the lead screw 1052 isrotational about the long axis of the housing 1022 Rotation of the drivecable 1050 thus results in rotation of the lead screw 1052. The leadscrew 1052 may be formed from a 300 series stainless steel 0-80 (or2-120) lead screw. A nut 1058 is rotationally mounted on the lead screw1052 and is used to translate rotational movement into linear movement.The nut 1058 may be made from, for example, brass and include an offsetthreaded hole 1059 for receiving the lead screw 1052. Rotation of thelead screw 1052 about its rotation axis thus causes the nut 1058 to moveaxially within the housing 1022. The nut 1058 is bonded or otherwiseaffixed to the actuating member 1030. When the actuating member 1030 isNITINOL wire, the end of the NITINOL wire may pass through a hole oraperture 1061 formed in the nut 1058. A plurality (e.g., four) of setscrews (not shown) may be threaded into holes or apertures 1063 tomechanically bind the actuating member 1030 to the nut 1058.

FIG. 68 illustrates a cross-sectional view of the implantable interface1010 according to another aspect of the invention The implantableinterface 1010 includes a housing 1062 in which is mounted a permanentmagnet 1064. The permanent magnet 1064 may be formed from, for example,a rare earth magnet such as Neodymium-Iron-Boron (NdFeB). The permanentmagnet 1064 is rod or cylindrically-shaped and is diametricallymagnetized (poles are perpendicular the long axis of the permanentmagnet 1064). As seen in FIG. 68 , aluminum plates or axles 1066 arebonded to either end of the permanent magnet 1064. The axles 1066 aredimensioned to fit within the inner races of ball bearings 1068 whichare mounted at opposing ends of the housing 1062. In this regard, thepermanent magnet 1064 is rotationally mounted within the housing 1062.The housing 1062 is formed from a non-magnetic material (e.g, plastic,polymer, titanium or aluminum) and is substantially sealed from theexternal environment so as to prevent bodily fluids and other materialsfrom entering the interior space, for example, with a siliconedip-coating.

Still referring to FIG. 68 , the proximal end of the drive cable sheath1026 (which is omitted from FIG. 68 for sake of clarity) may have aquick disconnect feature so that the drive cable 1050 and/or implantableinterface 1010 may be rapidly changed. In one aspect, the proximal endof the drive cable sheath 1026 includes a flanged end portion 1027 thatis dimensioned to abut a sheath retaining nut 1046 that engages withmating threads 1048 located at one end of the housing 1062. The flangedend portion 1027 and the retaining nut 1046 are permanently secured tothe drive cable sheath 1026. The retaining nut 1046 is preferablyrotationally secured and the flanged end portion 1027 is sealinglysecured. The flanged end portion 1027 is inserted through a seal 1065such as a compressible O-ring, which is nested within the housing 1062.The O-ring 1065 substantially seals the interface between drive cablesheath 1026 and the housing 1062 of the implantable interface 1010.

Still referring to FIG. 68 , one axle 1066 includes a recess 1070, forexample, in the shape of a hexagon or the like (female connector) thatreceives a correspondingly shaped keyed end 1072 of the drive cable 1050(male connector) as illustrated in FIG. 69 . FIG. 69 illustrates theproximal end of the drive cable 1050 cable including the keyed portion1072. With reference to FIGS. 68 and 69 , the implantable interface 1010is initially connected to the drive cable 1050 by inserting the keyedportion 1072 into the corresponding recess 1070 located in the axle1066. The sheath retaining nut 1046 can then be threaded and tightened,allowing the seal 1065 and the flanged end portion 1027 to form a sealedengagement between the drive cable sheath 1026 and the implantableinterface 1010. To de-couple the implantable interface 1010 a userunscrews the sheath retaining nut 1046 completely and withdraws thedrive cable sheath 1026. In this regard, a new drive cable 1050 and/orimplantable interface 1010 may be exchanged or changed as appropriate.

FIG. 70 illustrates an implantable obesity control system 1100 accordingto another embodiment of the invention and includes a restriction device1102, an implantable interface 1104, and a drive transmission 1106. Theimplantable obesity control system 1100 is similar to that illustratedin FIG. 64 with the exception that the drive cable 1050 has beenomitted. This embodiment thus uses a direct connection between the leadscrew 1112 and the permanent magnet 1118 (as shown in FIG. 71 ). Thereis no need for a separate drive cable 1050 or other transmission meansbetween the permanent magnet and the lead screw 1052. This embodiment isadvantageous because of the reduced number of components and the small,compact nature of the overall device.

FIG. 71 illustrates a cross-sectional view of the two housings 1108,1110. Housing 1108 includes lead screw 1112, nut 1114, and ball bearings1116 and may be sealed at the distal end via end cap 1109. The actuatingmember (not shown in FIG. 71 ) described above is secured to the nut1114 in via a receiving lumen 1115. Set screws (not shown) may be usedto mechanically engage the actuating member via a plurality of threadedapertures 1117. The remaining housing 1110 includes the permanent magnet1118 in addition an aluminum axle or spindle 1120 that is mounted to oneend of the magnet 1118 The proximal end of the lead screw 1112 may havea keyed portion (e.g., hexagonal-shaped tip or end) that fits within acorrespondingly-shaped recess or the like (not shown) in the axle 1120so that the implantable interface 1104 may be quickly changed.Alternatively, both housings 1108, 1110 could be replaced to exchange orchange-out the implantable interface 1104 It should be noted that only asingle bearing 1116 is needed to rotationally secure the magnet 1118within the housing 1110. The amount of torque on the opposing end of themagnet 1118 is relatively low so there is no need for an additionalbearing within the housing 1110. In configurations in which there is agreater torque (i.e., moment) on the opposing end of the magnet 1118, asecond bearing (not shown) can be used. The lead screw 1112 and magnet1118 are arranged serially in this configuration, but alternatively theycould be arranged in parallel, for example, wherein the magnet 1118imparts rotation to the lead screw 1112 via a pair of spur gears. Theparallel arrangement allows for a shorter overall length of the assemblyin relation to the serial arrangement, however the serial arrangementallows for a thinner, narrower assembly. The appropriate arrangement canbe chosen depending upon the desired clinical factors. For example, ifthe implantable interface is to be implanted in an area that undergoes alarge amount of bending, the shorter, parallel arrangement may bepreferred.

FIG. 72 illustrates an external magnetic driver 1130 according to oneaspect of the invention. The external magnetic driver 1130 may be usedto externally impart rotational motion or “drive” a permanent magnet(e.g., magnets 1064, 1118) located within an implantable interface(e.g., interfaces 1010, 1104). The external magnetic driver 1130includes a motor 1132 that is used to impart rotational movement to twopermanent magnets 1134, 1136. The motor 1132 may include, for example, aDC powered motor or servo that is powered via one or more batteries (notshown) integrally contained within the external magnetic driver 1130.Alternatively, the motor 1132 may be powered via a power cord or thelike to an external power source. For example, the external power sourcemay include one or more batteries or even an alternating current sourcethat is converted to DC.

Still referring to FIG. 72 , the two permanent magnets 1134, 1136 arepreferably cylindrically-shaped permanent magnets. The permanent magnetsmay be made from, for example, a rare earth magnet material such asNeodymium-Iron-Boron (NdFeB) although other rare earth magnets Forexample, each magnet 1134, 1136 may have a length of around 1.5 inchesand a diameter of around 1.0 to 3.5 inches. Both magnets 1134, 1136 arediametrically magnetized (poles are perpendicular the long axis of eachpermanent magnet 1134, 1136). The magnets 1134, 1136 may be containedwithin a non-magnetic cover or housing 1137. In this regard the magnets1134, 1136 are able to rotate within the stationary housing 1137 thatseparates the magnets 1134, 1136 from the external environment.Preferably, the housing 1137 is rigid and relatively thin walled atleast at the portion directly covering the permanent magnets 1134, 1136,in order to minimize the gap between the permanent magnets 1134, 1136and the internal magnet 1064.

As seen in FIG. 72 , the permanent magnets 1134, 1136 are rotationallymounted between opposing bases members 1138, 1140. Each magnet 1134,1136 may include axles or spindles 1142, 1144 mounted on opposing axialfaces of each magnet 1134, 1136. The axles 1142, 1144 may be mounted inrespective bearings (not shown) that are mounted in the base members1138, 1140. As seen in FIG. 72 , driven pulleys 1150 are mounted on oneset of axles 1142 and 1144. The driven pulleys 1150 may optionallyinclude grooves or teeth 1152 that are used to engage with correspondinggrooves or teeth 1156 (partially illustrated in FIG. 73 ) containedwithin a drive belt (indicated by path 1154).

Still referring to FIG. 72 , the external magnetic driver 1130 includesa drive transmission 1160 that includes the two driven pulleys 1150along with a plurality of pulleys 1162 a, 1162 b, 1162 c and rollers1164 a, 1164 b, 1164 c on which the drive belt 1154 is mounted Thepulleys 1162 a, 1162 b, 1162 c may optionally include grooves or teeth1166 used for gripping corresponding grooves or teeth 1156 of the drivebelt 1154. Pulleys 1162 a, 1162 b, 1162 c and rollers 1164 a, 1164 b,1164 c may be mounted on respective bearings (not shown) As seen in FIG.72 , pulley 1162 b is mechanically coupled to the drive shaft (notshown) of the motor 1132. The pulley 1162 b may be mounted directly tothe drive shaft or, alternatively, may be coupled through appropriategearing. One roller 1164 b is mounted on a biased arm 1170 and thusprovides tension to the belt 1154 The various pulleys 1150, 1162 a, 1162b, 1162 c and rollers 1164 a, 1164 b, 1164 c along with the drive belt1154 may be contained within a cover or housing 1172 that is mounted tothe base 1138 (as seen in FIG. 74 ).

As seen in FIGS. 72 and 73 , rotational movement of the pulley 1162 bcauses the drive belt 1154 to move around the various pulleys 1150, 1162a, 1162 b, 1162 c and rollers 1164 a, 1164 b, 1164 c In this regard,rotation movement of the motor 1132 is translated into rotationalmovement of the two permanent magnets 1134, 1136 via the drivetransmission 1160. In one aspect of the invention, the base members1138, 1140 are cut so as to form a recess 1174 that is located betweenthe two magnets 1134, 1136. During use, the external magnetic driver1130 is pressed against the skin of a patient, or against the clothingwhich covers the skin (e.g, the external driver 1130 may be used throughclothing so the patient may not need to undress). The recess 1174 allowsskin as well as the underlying tissue to gather or compress within therecessed region 1174. This advantageously reduces the overall distancebetween the external drive magnets 1134, 1136 and the magnet 1064, 1118contained within the implantable interface 1010, 1104. By reducing thedistance, this means that the externally located magnets 1134, 1136and/or the internal magnet (e.g., 1064, 1118) may be made smaller.

Still referring to FIGS. 72 and 73 , the external magnetic driver 1130preferably includes an encoder 1175 that is used to accurately andprecisely measure the degree of movement (e g., rotational) of theexternal magnets 1134, 1136. In one embodiment, an encoder 1175 ismounted on the base member 1138 and includes a light source 1176 and alight receiver 1178 The light source 1176 may include a LED which ispointed or directed toward pulley 1162 c. Similarly, the light receiver1178 may be directed toward the pulley 1162 c. The pulley 1162 cincludes a number of reflective markers 1177 regularly spaced about theperiphery of the pulley 1162 c. Depending on the rotational orientationof the pulley 1162 c, light is either reflected or not reflected backonto the light receiver 1178 The digital on/off signal generated by thelight receiver 1178 can then be used to determine the rotational speedand displacement of the external magnets 1134, 1136

FIGS. 75A, 75B, 75C, and 75D illustrate the progression of the externalmagnets 1134, 1136 and the internal magnet 1064 that is located withinthe implantable interface 1010 during use. Internal magnet 1064 is shownfor illustration purposes. It should be understood that the internalmagnet may also include, for example, internal magnet 1118 that islocated within the implantable interface 1104 according to thatalternative embodiment FIGS. 75A, 75B, 75C, and 75D illustrate theexternal magnetic driver 1130 being disposed against the externalsurface of the patient’s skin 1180 The external magnetic driver 1130 isplaced against the skin 1180 in this manner to remotely rotate theinternal magnet 1064. As explained herein, rotation of the internalmagnet 1064 is translated into linear motion via the drive transmission1020 to controllable adjust the stoma or opening in the restrictiondevice 1002 mounted about a body lumen, such as, the patient’s stomach.

As seen in FIGS. 75A, 75B, 75C, and 75D, the external magnetic driver1130 may be pressed down on the patient’s skin 1180 with some degree offorce such that skin and other tissue such as the underlying layer offat 1182 are pressed or forced into the recess 1174 of the externalmagnetic driver 1130. The implantable interface (e.g., 1010, 1104) whichcontains the internal magnet 1064 (which is contained in a housing 1062not shown in FIGS. 75A, 75B, 75C, and 75D) is secured to the patient inan artificially created opening or passageway formed in or adjacent tothe fascia layer 1184 separating the layer of fat 1182 from underlyingabdominal muscle tissue 1186. Underneath the abdominal muscle tissue1186 is the peritoneum 1188. Typically, as explained herein, theimplantable interface 1104 is secured to the patient via a clamp,sutures, screws, retaining members, or the like. FIGS. 75A, 75B, 75C,and 75D omit these elements for sake of clarity to just show themagnetic orientation of the internal magnet 1064 as it undergoes a fullrotation in response to movement of the permanent magnets 1134, 1136 ofthe external magnetic driver 1130.

With reference to FIG. 75A, the internal magnet 1064 is shown beingoriented with respect to the two permanent magnets 1134, 1136 via anangle θ This angle θ may depend on a number of factors including, forinstance, the separation distance between the two permanent magnets1134, 1136, the location or depth of where the implantable interface1104 is located, the degree of force at which the external magneticdriver 1130 is pushed against the patient’s skin Generally, the angle θshould be at or around 90° to achieve maximum drivability (e.g.,torque).

FIG. 75A illustrates the initial position of the two permanent magnets1134, 1136 and the internal magnet 1064 This represents the initial orstarting location (e.g., 0° position as indicated). Of course, it shouldbe understood that, during actual use, the particular orientation of thetwo permanent magnets 1134, 1136 and the internal magnet 1064 will varyand not likely will have the starting orientation as illustrated in FIG.75A. In the starting location illustrated in FIG. 75A, the two permanentmagnets 1134, 1136 are oriented with their poles in an N—S/S—Narrangement. The internal magnet 1064 is, however, oriented generallyperpendicular to the poles of the two permanent magnets 1134, 1136.

FIG. 75B illustrates the orientation of the two permanent magnets 1134,1136 and the internal magnet 1064 after the two permanent magnets 1134,1136 have rotated through 90°. The two permanent magnets 1134, 1136rotate in the direction of arrow A (e.g., clockwise) while the internalmagnet 1064 rotates in the opposite direction (e.g., counter clockwise)represented by arrow B. It should be understood that the two permanentmagnets 1134, 1136 may rotate in the counter clockwise direction whilethe internal magnet 1064 may rotate in the clockwise direction. Rotationof the two permanent magnets 1134, 1136 and the internal magnet 1064continues as represented by the 180° and 270° orientations asillustrated in FIGS. 75C and 75D. Rotation continues until the startingposition (0°) is reached again.

During operation of the external magnetic driver 1130. the permanentmagnets 1134, 1136 may be driven to rotate the internal magnet 1064through one or more full rotations in either direction to tighten orloosen the restriction device 1002 as needed. Of course, the permanentmagnets 1134, 1136 may be driven to rotate the internal magnet 1064through a partial rotation as well (e.g, ¼, ⅛, 1/16, etc). The use oftwo magnets 1134, 1136 is preferred over a single external magnetbecause the driven magnet (e.g., 1064, 1118) may not be orientedperfectly at the start of rotation, so one external magnet 1134, 1136may not be able to deliver its maximum torque, which depends on theorientation of the internal driven magnet (e.g., 1064, 1118) to somedegree. However, when two (2) external magnets (1134, 1136) are used,one of the two 1134 or 1136 will have an orientation relative to theinternal driven magnet (e.g., 1064, 1118) that is better or more optimalthan the other. In addition, the torques imparted by each externalmagnet 1134, 1136 are additive.

While the external magnetic driver 1130 and implantable interface 1010,1104 have generally been described as functioning using rotationalmovement of driving elements (i.e., magnetic elements) it should beunderstood that non-rotational movement can also be used to drive oradjust the restriction device 1002, 1102. For example, linear or slidingmotion back-and-forth may also be used to adjust the restriction device1002, 1102. In this regard, a single magnet located internal to thepatient that slides back-and-forth on a slide or other base can be usedto adjust the restriction device 1002, 1102 using a ratchet-type deviceThe sliding, internal magnet may be driven via one or moreexternally-located permanent/electromagnets that slides or moveslaterally (or moves the magnetic field) in a similar back-and-forthmanner. Rotational movement of the externally-located magneticelement(s) may also be used to drive the internal magnet

In still another alternative, permanent magnets may be located on apivoting member that pivots back and forth (like a teeter-totter) abouta pivot point. For example, a first permanent magnet having a North poleoriented in a first direction may be located at one end of the pivotingmember while a permanent magnet having a South pole oriented in thefirst direction is located at the other end of the pivoting member. Aratchet-type device may be used to translate the pivoting movement intolinear movement that can actuate or adjust the restriction device 1002,1102. The first and second internally-located permanent magnets may bedriven by one or more externally located magnetic elements (eitherpermanent or electromagnets). External motion of the electric field bylinear or even rotational movement may be used to the drive the pivotingmember.

While certain embodiments of the gastric restriction systems discussedherein have been described as using a restriction device that is coupledto a separate implantable interface via a drive transmission, it shouldbe understood that the various components could be integrated into asingle device. For example, a single restriction device may include orbe closely associated with the constituent components of the implantableinterface and drive transmission This, of course, would reduce theoverall length of the device by integrating these components into asingle device which may be placed around, for instance, the stomach ofthe patient.

FIG. 76 illustrates a system 1076 according to one aspect of theinvention for driving the external magnetic driver 1130. FIG. 76illustrates the external magnetic driver 1130 pressed against thesurface of a patient 1077 (torso shown in cross-section). Theimplantable interface 1010 located within the body cavity along with theadjustable body 1004 are illustrated. The permanent magnet (e.g., thedriven magnet) that is located within the implantable interface 1010located inside the patient 1077 is magnetically coupled through thepatient’s skin and other tissue to the two external magnets 1134, 1136located in the external magnetic driver 1130. As explained herein, onerotation of the external magnets 1134, 1136 causes a correspondingsingle rotation of the driven magnet (e.g., magnets 1064 or 1118)located within the implantable interface (e.g., 1010, 1104). Turning thedriven magnet 1064, 1118 in one direction causes the restriction device(e.g., 1002, 1102) to close while turning in the opposite directioncauses the restriction device (e.g., 1002, 1102) to open. Changes to theopening or stoma in the restriction device 1002, 1102 are directlyproportional to the number of turns of the driven magnet 1064, 1118.

The motor 1132 of the external magnetic driver 1130 is controlled via amotor control circuit 1078 operatively connected to a programmable logiccontroller (PLC) 1080. The PLC 1080 outputs an analog signal to themotor control circuit 1078 that is proportional to the desired speed ofthe motor 1132 The PLC 1080 may also select the rotational direction ofthe motor 1132 (i.e., forward or reverse). In one aspect, the PLC 1080receives an input signal from a shaft encoder 1082 that is used toidentify with high precision and accuracy the exact relative position ofthe external magnets 1134, 1136. For example, the shaft encoder 1082 maybe an encoder 1175 as described above. In one embodiment, the signal isa pulsed, two channel quadrature signal that represents the angularposition of the external magnets 1134, 1136. The PLC 1080 may include abuilt-in screen or display 1081 that can display messages, warnings, andthe like. The PLC 1080 may optionally include a keyboard 1083 or otherinput device for entering data. The PLC 1080 may be incorporateddirectly into the external magnetic driver 1130 or it may be a separatecomponent that is electrically connected to the main external magneticdriver 1130.

In one aspect of the invention, a sensor 1084 is incorporated into theexternal magnetic driver 1130 that is able to sense or determine therotational or angular position of the driven magnet 1064, 1118. Thesensor 1084 may acquire positional information using, for example, soundwaves, ultrasonic waves, light, radiation, or even changes orperturbations in the electromagnetic field between the driven magnet1064, 1118 and the external magnets 1134, 1136. For example, the sensor1084 may detect photons or light that is reflected from the drivenmagnet 1064, 1118 or a coupled structure (e.g., rotor) that is attachedthereto. For example, light may be passed through the patient’s skin andother tissue at wavelength(s) conducive for passage through tissue.Portions of the driven magnet 1064, 1118 or associated structure mayinclude a reflective surface that reflects light back outside thepatient as the driven magnet 1064, 1118 moves. The reflected light canthen be detected by the sensor 1084 which may include, for example, aphotodetector or the like.

In another aspect, the sensor 1084 may operate on the Hall effect,wherein two additional magnets are located within the implantableassembly. The additional magnets move axially in relation to each otheras the driven assembly rotates and therefore as the restriction deviceconstricts or loosens, allowing the determination of the current size ofthe restriction device.

In the embodiment of FIG. 76 , the sensor 1084 is a microphone disposedon the external magnetic driver 1130. For instance, the microphonesensor 1084 may be disposed in the recessed portion 1174 of the externalmagnetic driver 1130. The output of the microphone sensor 1084 isdirected to a signal processing circuit 1086 that amplifies and filtersthe detected acoustic signal. In this regard, the acoustic signal mayinclude a “click” or other noise that is periodically generated byrotation of the driven magnet 1064, 1118. For example, the driven magnet1064, 1118 may click every time a full rotation is made. The pitch ofthe click may differ depending on the direction of rotation. Forexample, rotation in one direction (e.g., tightening) may produce a lowpitch while rotation in the other direction (e.g., loosening) mayproduce a higher pitch signal (or vice versa). The amplified andfiltered signal from the signal processing circuit 1086 can then pass tothe PLC 1080.

During operation of the system 1076, each patient will have a number orindicia that corresponds to the current diameter or size of theirrestriction device 1002, 1102. For example, a fully open restrictiondevice 1002, 1102 may have a diameter or size of around 2.90 cm while afully closed device 1002, 1102 may have a diameter or size of around1.20 cm. This number can be stored on a storage device 1088 (as shown inFIG. 76 ) that is carried by the patient (e.g., memory card, magneticcard, or the like) or is integrally formed with the implantable system(e.g., systems 1000, 1100). For example, a RFID tag 1088 implantedeither as part of the system or separately may be disposed inside thepatient (e.g., subcutaneously or as part of the device) and can be readand written via an antenna 1090 to update the current size of therestriction device 1002, 1102. In one aspect, the PLC 1080 has theability to read the current number corresponding to the diameter or sizeof the restriction device 1002, 1102 from the storage device 1088 ThePLC 1080 may also be able to write the adjusted or more updated currentdiameter or size of the restriction device 1002, 1102 to the storagedevice 1088. Of course, the current size may record manually in thepatient’s medical records (e.g., chart, card or electronic patientrecord) that is then viewed and altered, as appropriate, each time thepatient visits his or her physician.

The patient, therefore, carries their medical record with them, and if,for example, they are in another country and need to be adjusted, theRFID tag 1088 has all of the information needed. Additionally, the RFIDtag 1088 may be used as a security device. For example, the RFID tag1088 may be used to allow only physicians to adjust the restrictiondevice (1002, 1102) and not patients. Alternatively, the RFID tag 1088may be used to allow only certain models or makes of restriction devicesto be adjusted by a specific model or serial number of external magneticdriver 1130.

In one aspect, the current size or diameter of the restriction device1002, 1102 is input into the PLC 1080 This may be done automatically orthrough manual input via, for instance, the keyboard 1083 that isassociated with the PLC 1080. The PLC 1080 thus knows the patient’sstarting point. If the patient’s records are lost, the PLC 1080 may beprogrammed to fully open the restriction device 1002, 1102 which is, ofcourse, a known starting point. The number of turns required to meet thefully open position may be counted by the PLC 1080 and the restrictiondevice 1002, 1102 can then be returned to the same restriction point.

The external magnetic driver 1130 is commanded to make an adjustmentThis may be accomplished via a pre-set command entered into the PLC 1080(e.g., reduce size of restriction device 1002, 1102 by 0.5 cm). The PLC1080 configures the proper direction for the motor 1132 and startsrotation of the motor 1132. As the motor 1132 spins, the encoder 1082 isable to continuously monitor the shaft position of the motor directly,as is shown in FIG. 76 , or through another shaft or surface that ismechanically coupled to the motor 1132. For example, the encoder 1082may read the position of markings 1177 located on the exterior of apulley 1162 c like that disclosed in FIG. 72 . Every rotation or partialrotation of the motor 1132 can then be counted and used to calculate theadjusted or new size of the restriction device 1002, 1102.

The sensor 1084, which may include a microphone sensor 1084, may bemonitored continuously. For example, every rotation of the motor 1132should generate the appropriate number and pitch of clicks generated byrotation of the permanent magnet inside the implant 1010 (or implant1104). If the motor 1132 turns a full revolution but no clicks aresensed, the magnetic coupling may have been lost and an error messagemay be displayed to the operator on the display 1081 of the PLC 1080.Similarly, an error message may be displayed on the display 1081 if thesensor 1084 acquires the wrong pitch of the auditory signal (e.g., thesensor 1084 detects a loosening pitch but the external magnetic driver1130 was configured to tighten).

FIG. 77 illustrates a mount 1200 according to one aspect of theinvention that is used to secure the implantable interface 1010 (orimplantable interface 1104) to the patient. The mount 1200 may be usedto secure a variety of implantable apparatuses beyond the implantableinterfaces discussed herein. This includes, for example, injection portsand other implantable interfaces usable with, for example, a gastricrestriction device The mount 1200 includes a base 1202 having aplurality of holes 1204 dimensioned for passage of fasteners 1210 (shownin FIGS. 78, 79A, 79B, 79D, 79E, 80, 81, 82 ). The mount 1200 alsoincludes a receiving portion 1206 that is dimensioned to receive theimplantable interface 1010. As seen in FIG. 77 , the receiving portion1206 is shaped in a hemi-cylindrical manner configured to receive thecylindrical shape of the implantable interface 1010. The receivingportion 1206 may be dimensioned such that the implantable interface 1010forms a friction or snap-fit within the mount 1200. For example, in oneaspect of the invention, prior to fastening the mount 1200 to thepatient’s tissue, the implantable interface 1010 is secured to the mount1200. Of course, in an alternative aspect, the implantable interface1010 may be inserted or slid into the receiving portion 1206 after themount 1200 is secured to the patient. In another alternativeconfiguration, the mount 1200 may be configured as the implantableinterface itself (as shown in FIG. 82 ).

FIG. 78 illustrates a fastening tool or instrument 1220 that is used torapidly and securely affix the mount 1200 to the patient’s tissue. Thefastening tool 1220 includes an elongate shaft 1222 with a proximallymounted knob 1224. A grip or handle 1226 is located on the elongateshaft 1222 and is used by the physician to grasp the fastening tool 1220during the placement process. The distal end of the fastening tool 1220includes a driving element 1228 that contains a recess or socket 1230for holding the mount 1200 Fastening tool 1220 is used to drive aplurality of fasteners 1210 through respective holes 1204 in the base1202 to fixedly secure the mount 1200 to the patient’s tissue Asexplained in more detail herein, rotational movement of the knob 1224turns a central sun gear that, in turn, drives a series of outer gearswithin the fastening tool 1220 to rotate the individual fasteners 1210.Rotational movement of the knob 1224 also moves the driving element 1228in the direction of arrow A to either extend or retract the drivingelement 1228 depending on direction of rotation of the knob 1224.

FIG. 79A illustrates a side view of the driving element 1228 holding themount 1200 and illustrating the fasteners 1210 in the fully deployed(e.g, extended) position FIG. 79B illustrates a cross-sectional viewtaken along the line B-B′ of FIG. 79A. FIG. 79C illustrates across-sectional view taken along the line C-C′ of FIG. 79A. The drivingelement 1228 generally includes a lower base or interface 1232 on whichare mounted a central gear 1236 and a plurality of outer gears 1238(four are illustrated in FIG. 79C. Rotation of the central gear 1236thus causes each of the four outer gears 1238 to rotate as well.

FIG. 79D illustrates a perspective view of the base 1232 portion of thedriving element 1228. As seen in FIG. 79D each of the outer gears 1238is coupled to a corresponding shaft or driver 1240 (shown in phantom)that has as distal end configured for engaging with the fasteners 1210For example, the distal end of the driver 1240 may include a keyedportion (e.g., hexagonally-shaped end) that mates with acorrespondingly-shaped recess (e.g., hex-shaped recess) in the fastener1210. The drivers 1240 are thus rotationally mounted within the base1232. Rotation of the central gear 1236 turns the outer gears 1238 whichthen turns the corresponding drivers 1240. Each driver 1240 is mountedwithin a barrel or tube 1252 (also shown in phantom) having a lumentherein dimensioned for passage of the driver 1240. The barrels or tubes1252 may be machined, drilled, or molded within the base portion 1232 ofthe driving element 1228. FIG. 80 illustrates a partially exploded viewshowing the drivers 1240 disposed within respective barrels 1252.

Referring back to FIG. 79D, a plate 1242 is mounted above the centralgear 1236 and outer gears 1238 and is used as a bearing surface that isused to move the base 1232 up or down as the knob 1224 is turned. A hub1244 is located above the plate 1242 and is coupled to the central gear1236. Rotation of the hub 1244 thus results in rotation of the centralgear 1236. The hub 1244 includes a hole or recess 1246 for receiving adrive shaft 1250 (as seen in FIG. 80 ). The drive shaft 1250 may befixedly secured to the hub 1244 using a set screw (not shown) that isinserted into the hub 1244 via aperture 1248. As seen in FIG. 79E, thedriving element 1230 includes an upper housing 1234 that providesclearance for the base 1232 to move axially as the knob 1224 is turned.This allows for controlled delivery into the fascia

As an alternative to the central gear 1236 which turns the outer gears1238, the central gear 1236 may be omitted and an outer ring gear (notshown) having internal teeth may be used to engage and rotate the outergears 1238. The advantage of this embodiment is that, as the physicianturns the knob 1224 clockwise, the fasteners 1210 turn clockwise. Withthe central sun gear 1236, the fasteners 1210 have to be made left-handwound and they turn counter-clockwise when the physician tightens theknob 1224 in the clockwise direction. The advantage of the central gear1236 is that it requires less torque for the physician to turn the knob1224.

FIG. 80 illustrates a partially exploded view of the distal end of thefastening tool 1220. In the assembled configuration, the drive shaft1250 rotates in response to rotational movement of the proximallylocated knob 1224 In addition, the drive shaft 1250 moves axially withinthe length of the shaft 1222 in response to rotation of the knob 1224.Each fastener 1210 is thus moveable axially in the direction of arrow Aand rotationally in the direction of arrow B. FIG. 80 illustrates fourfasteners 1210 mounted at the end of each driver 1240. The fourfasteners 1210 would pass through respective holes 1204 in the mount1200 (as shown in FIG. 77 ). It should be noted that in one alternativeembodiment the fasteners 1210 may be permanently, rotationally securedin the mount 1200.

FIG. 81 illustrates a perspective view of a fastener 1210. The fastener1210 may include a head 1212 portion along with a coil portion 1214 Thehead 1212 may be formed separately and bonded to the coil 1214 or thehead 1212 and coil 1214 may be formed in an integrated manner. The head1212 and coil 1214 may be formed from a biocompatible metallic materialsuch as stainless steel, NITINOL, or the like. It may be preferred thata non-magnetic material like NITINOL or Titanium is used for all of theportions of the fastener 1210, so that there is no effect by any of themagnets, for example, during the adjustment procedure. While FIG. 81illustrates a single coil 1214 originating from the head 1212, in otherembodiments, there may be multiple, nested coils 1214 with differentpitches affixed or otherwise mounted to a single head 1212. Theadditional coils 1214 may impart added anchoring ability. Duringsecuring, the coil 1214 may turn in the clockwise direction asillustrated in FIG. 81 or, alternatively, the coil 1214 may turn in thecounter-clockwise direction. The coil 1214 may include a sharpened tipor end 1215 to aid in penetrating the tissue A simple beveled tip isideal. If the tip is too sharp, it can cause the patient more pain. Thehead 1212 preferably includes a recess 1216 that is dimensioned tointerface with the distal end of the drivers 1240. For example, asillustrated in FIG. 81 , the recess 1216 is hexagonally-shaped which canthen receive the hexagonally-shaped distal end of the drivers 1240 Thefastener 1210 may have a coil length of 4 mm or less. In addition, thewire forming the coil 1214 may have a diameter of around 0.020 inchesand the coil 1214 may have an OD of around 0.100 inches and ID of around0.060 inches. The diameter of the head 1212 is around 0.150 inches.

In one aspect of the invention, the fasteners 1210 are pre-loaded intothe fastening tool 1220 prior to use In addition, the mount 1200 mayalso be pre-loaded into the fastening tool 1220. In an alternate aspect,however, the mount 1200 may be loaded manually by the physician orsurgeon prior to use. The fasteners 1210 may include a number retentionmeans so that the fasteners 1210 do not prematurely fall out of thefastening tool 1220. For example, the ends of the drivers 1240 mayinclude a bump, detent, or tab that locks into the recess 1216 of thefastener head 1212. Alternatively, an adhesive or the like may be usedtemporarily secure the fastener 1210 to the end of the drivers 1240. Instill another alternative, an elastomeric membrane, ring or washer maybe interposed between the fastener head 1212 and the barrel 1252 toprovide a friction fit between the two to prevent premature release. Itshould be noted that the mount 1200 may be affixed to the internal orexternal wall of the patient’s abdomen as described in more detailbelow.

FIG. 82 illustrates a perspective view of a mount 1300 that is used tohold or otherwise secure a cylindrically-shaped permanent magnet 1302.The permanent magnet 1302 is the “driven” magnet that is rotationallyhoused within the implantable interface (e.g., implantable interfaces1010 and 1104). The mount 1300 includes an acoustic or sonic indicatorhousing 1304 that contains a magnetic ball 1306 The interior of thehousing 1304 includes a groove or track 1305 dimensioned to permitmovement of the magnetic ball 1306 (e.g., rolling motion). It is alsocontemplated that other magnetic structures capable of movement withinthe housing 1304 may also be used. For example, a roller or cylinder maybe used in place of the magnetic ball 1306. Still referring to FIG. 82 ,first and second impact surfaces 1308, 1310 are disposed on opposingends of the track 1305. The first and second impact surfaces 1308, 1310may include a plate, tine(s), or other projection that prohibits orstops movement of the magnetic ball 1306 In one aspect, the mount 1300is secured to the fascia by one or more helical fasteners 1312. Ofcourse, sutures or other fasteners may also be used to fixedly securethe mount 1300 to the patient.

The mount 1300 may also include a resonance chamber for amplifying thesound created by the magnetic ball 1306 and the first and second impactsurfaces 1308, 1310. For example, the sonic indicator housing 1304itself may made from an appropriate material and/or have an appropriatewall thickness or chamber size, so that it acts as the resonance chamberitself. Another manner of creating a resonance chamber is by securingthe mount 1300 to a more resonant portion of the body, for example abony structure such as the sternum. The mount 1300 may be secured to thefascia covering the sternum via the subcutaneous securement method, orit may be attached to the intra-abdominal wall, behind the sternum, orit may be attached to the sternum directly via bone screws or the likeAlternatively, the mount 1200 depicted in FIG. 77 may be configured toact as a resonant structure.

FIGS. 83 through 98 schematically illustrate the acoustic indicatorhousing 1304 and driven magnet 1302 as the driven magnet 1302 is rotatedin both the clockwise directions (arrow A) and counter-clockwisedirections (arrow B). The mount 1300 is used to create an acousticsignal (e.g., a click) that can be used to count rotational movement ofthe driven magnet 1302 and also determine its rotational direction. Anacoustic signal (i.e., sound) is generated when the magnetic ball 1306strikes either the first impact surface 1308 or the second impactsurface 1310. FIGS. 83-90 illustrate rotation of the driven magnet 1302in the clockwise direction (arrow A) while FIGS. 91-98 illustraterotation of the driven magnet 1302 in the counter-clockwise direction(arrow B). When the driven magnet 1302 is rotated in the clockwisedirection, the magnetic ball 1306 strikes the first impact surface 1308two times (2×) per full rotation, with the first impact surface 1308producing sound with a first amplitude and/or frequency When the drivenmagnet 1302 is rotated in the counter-clockwise direction, the magneticball 1306 strikes the second impact surface 1310 two times (2×) per fullrotation, with the second impact surface 1310 producing sound with asecond amplitude and/or frequency.

As illustrated in FIGS. 83-98 , the first impact surface 1308 is thinnerthan the second impact surface 1310, and thus, the first impact surface1308 is configured to resonate at a higher frequency than the secondimpact surface 1310. Alternatively, the difference in frequency can beachieved by making the first impact surface 1308 from a differentmaterial than the second impact surface 1310. Alternatively, theamplitude of acoustic signal generated by the magnetic ball 1306 hittingthe first and second impact surfaces 1308, 1310 may be used todiscriminate rotational direction For example, clockwise rotation mayproduce a relatively loud click while counter-clockwise rotation mayproduce a relatively quiet click.

The magnetic ball 1306 is made from a magnetic material, for example 400series stainless steel. The magnetic ball 1306 is attracted to both thesouth pole 1314 of the driven magnet 1302 and the north pole 1316 of thedriven magnet 1302. As seen in FIG. 83 , the driven magnet 1302 beginsto rotate in the clockwise direction (arrow A) As pictured, the startingpoint of the magnetic ball 1306 is adjacent to the north pole 1316 ofthe magnet 1302. As seen in FIG. 84 , as the magnet 1302 rotates, themagnetic ball 1306 follows the north pole 1316. This continues until, asshown in FIG. 85 , the magnetic ball 1306 is stopped by the secondimpact surface 1310. Now, as seen in FIG. 86 , the magnetic ball 1306 istrapped against the second impact surface 1310, while the driven magnet1302 continues to rotate. The magnetic ball 1306 may roll at this point,but it is forced against the second impact surface 1310 by itsattraction to the north pole 1316 of the magnet 1302, until the southpole 1314 becomes substantially closer to the magnetic ball 1306 asshown in FIG. 87 , at which point the magnetic ball 1306 acceleratestowards the first impact surface 1308 in the direction of arrow α,thereby hitting it (as seen in FIG. 88 ) and creating an acoustic signalor sound having a greater intensity than when the magnetic ball 1306 wasstopped by the second impact surface 1310. Now, as the driven magnet1302 continues to turn, the magnetic ball 1306 follows the south pole1314 of the driven magnet 1302 as seen in FIG. 89 , and continues tofollow the south pole 1314 until the magnetic ball 1306 is stopped bythe second impact surface 1310 as seen in FIG. 90 .

FIGS. 91-98 illustrate the acoustic mechanism being activated bycounter-clockwise rotation of the driven magnet 1302. In this process,the first impact surface 1308 serves to stop the magnetic ball 1306, andthe magnetic ball 1306 accelerates and impacts the second impact surface1310, creating a different acoustic signal. For example, the differentacoustic signal may include a louder signal or a signal with a differentfrequency (e.g., pitch). In FIG. 91 , the driven magnet 1302 begins torotate in the counter-clockwise direction (arrow B). As illustrated, thestarting point of the magnetic ball 1306 is adjacent the south pole 1314of the magnet 1302. As seen in FIG. 92 , as the magnet 1302 rotates, themagnetic ball 1306 follows the south pole 1314. This continues until, asshown in FIG. 93 , the magnetic ball 1306 is stopped by the first impactsurface 1308. As seen in FIG. 93 , the magnetic ball 1306 is trappedagainst the first impact surface 1308, while the driven magnet 1302continues to rotate The magnetic ball 1306 may roll at this point, butit is forced against the first impact surface 1308 by its attraction tothe south pole 1314 of the magnet 1302, until the north pole 1316becomes closer to the magnetic ball 1306 as shown in FIG. 94 , at whichpoint the magnetic ball 1306 accelerates towards the second impact plate1310 in the direction of arrow β, thereby hitting the second impactplate 1310 (as seen in FIG. 95 ) and creating an acoustic signal orsound having a greater intensity than when the magnetic ball 1306 wasstopped by the first impact surface 1308. Now, as the magnet 1302continues to turn, the magnetic ball 1306 follows the north pole 1316 ofthe magnet 1302 as seen in FIG. 97 , and continues to follow the northpole 1316 until the magnetic ball 1306 is stopped by the first impactsurface 1308 as illustrated in FIG. 98 .

It can be appreciated that each turn of the magnet 1302 creates two (2)relatively loud strikes, which can be detected by a non-invasive,external device comprising a sonic sensor, for example, a microphone(e.g., sensor 1084 in FIG. 76 ). If, for example, the magnet 1302 isturning a 0-80 lead screw (e.g., 1052, 1112) to tighten the restrictiondevice (1002, 1102), then each turn represents 1/80 of an inch in thechange of circumference, and thus each half turn represents 1/160 of aninch, or 0.00625″. By dividing by PI this represents 0.002″diametricalchange of the restriction device (1002, 1102) per half turn, or 0.05 mm.This is even less than the expected precision needed for operation,which is believed to be around 0.2 mm.

It can also be appreciated that the acoustic signal or sound made by thestrike due to the acceleration of the magnetic ball 1306 against thefirst impact surface 1308 during clockwise rotation of the magnet 1302will contain a different frequency spectrum than the acoustic signal orsound made by the strike due to the acceleration of the magnetic ball1306 against the second impact surface 1310 during counter-clockwiserotation of the magnet 1302. The mount 1300 thus provides a relativelysimple, low-cost device in which the direction of the rotation (i.e.,increasing diameter vs. decreasing diameter) can be automaticallyidentified. Further, the mount 1300 is able to determine the exactnumber of half rotations in each direction.

The mount 1300 may be operatively integrated with a programmable logiccontroller (PLC) such as the PLC 1080 described herein. In this regard,the exact diameter of the restriction device 1002, 1102 can bedetermined The PLC 1080 is able to identify the direction of rotationvia the frequency of sound, and then change the direction of rotation ifthis is not the desired direction. The PLC 1080 is also able to countthe number of half rotations until amount of restriction is achieved. Ifthere is any slip between the magnets 1134, 1136 of the external device1130 and the driven magnet 1302, the PLC 1080 will not detect theacoustic signal and thus will not count these as rotations.

When the mount 1300 is implanted in a patient, the physician may beunaware of its orientation. Because of this, it is not known by thephysician which direction of rotation of the external device magnetswill cause tightening and which will cause loosening. The PLC 1080.however, will be able to immediately identify the correct direction ofrotation by the detected frequency.

For example, FIG. 99 illustrates the sound 1320 detected fromcounter-clockwise rotation of the magnet 1302 and FIG. 100 illustratesthe sound 1324 detected from clockwise rotation. There may be additionalbackground acoustic signals or noise 1328 created by, for example, thesound of the motor 1132 of the external device 1130. In both rotationdirections, the acoustic “clicks” 1320 and 1324 look very similar toeach other. However, by analyzing the frequency spectrum of the clicks,one is able to discern differences between clockwise andcounter-clockwise rotation of the magnet 1302. As seen in FIG. 101 , thefrequency spectrum for the counter-clockwise rotation is centered atabout 14 kHz, while the spectrum for clockwise rotation (FIG. 102 ) iscentered at about 18 kHz. This shift or change in center frequency canbe used as a basis for determining the absolute rotational direction ofthe magnet 1302.

Gastric restriction-based devices for obesity control are all currentlyplaced with their interface portion located subcutaneously.Hydraulic-based gastric restriction devices have injection ports thatare relatively large, and the method of placing these devices is usuallyone of the two following methods. The first method involves placing theentire device, with the exception of the port, through a 15 mm trocarinto the insufflated abdominal cavity The second method involves placingand then removing a 12 mm trocar and then placing the restriction device(without the port) into the abdominal cavity through the remaining tractin the tissue. In this second method, the 12 mm trocar is then replacedin order to maintain insufflation pressure. In both of these methods,however, an incision must be made in the skin near the trocar site inorder to make a large enough passage through the skin for passage of theport. The fat is then separated from the fascia for a large enough areato allow the port to be secured to the fascia, usually with suture Theskin is then sutured to close the site The various trocar sizesdiscussed herein refer to the commercial sizes of trocars used byphysicians and surgeons. For example, a 12 mm trocar may have an outsidediameter (OD) that is greater than 12 mm but the trocar is stillreferred to as a ″12 mm trocar.″

In contrast to existing systems, the present obesity control system hasa comparatively small overall cross-sectional diameter throughout itsentire length, and the device has the option of being placed with theimplantable interface located either in a subcutaneous position, or theentire device can be placed completely intra-abdominally In eitherconfiguration, the relatively large incision heretofore required for theinjection ports is not necessary. Because the entire device can fit downa 12 mm trocar, this incision is not required. The reason for thesmaller overall cross-section diameter is multifold First, therestriction device is non-inflatable, and thus it does not require thespace in the cross-section for the annular inflation lumen, nor thethick walls of the inflatable area necessary for resisting the stressdue to the inflation pressure. In addition, the size of the magnetrequired to impart the necessary torque is significantly smaller thanthe inflation ports that are used with the hydraulic restriction devicedesigns.

FIG. 103 illustrates a sagittal (i.e., lateral) section of an obesepatient 1500 prior to laparoscopic implantation of the inventive obesitycontrol system. The abdominal cavity 1510 is located between theabdominal wall 1512 and the spine 1508. It should be noted that many ofthe major organs are not depicted for clarity’s sake. The stomach 1506can be seen beneath the liver 1504. The sternum 1502 and diaphragm 1503are also depicted, as is the naval 1514.

In FIG. 104 a 12 mm trocar 1516 is placed through the abdominal wall1512, for example above the navel 1514, so that the tip of the trocar1516 extends into the abdominal cavity 1510. Insufflation is thencreated, for example by injecting CO₂ through a Luer connection in thetrocar 1516 at a pressure of 15 mm Hg. Insufflation of the body cavityallows for enough separation such that other trocars may be safelyplaced and organs can be better identified. As seen in FIG. 105 , theinventive obesity control system 1518, including restriction device1520, implantable interface 1524 and drive transmission 1522 can becompletely placed through the 12 mm trocar 1516 with the use of a 5 mmgrasper 1532, which comprises a grasping tip 1530, a shaft 1526 and ahandle 1528. The restriction device 1520 is grasped by the grasping tip1530 of the 5 mm grasper 1532 and the obesity control system is placedinto the abdominal cavity 1510.

Because of the small dimensions of the restriction device 1520 and drivetransmission 1522, the shaft 1526 of the 5 mm grasper 1532 can be placedin parallel with the restriction device 1520 and drive transmission1522, until the restriction device 1520 is located completely within theabdominal cavity 1510 The 5 mm grasper 1532 is then manipulated at thehandle 1528 so that the grasping tip 1530 releases the restrictiondevice 1520. The 5 mm grasper 1532 is then removed, and can be used tohelp push the implantable interface 1524 completely through the 12 mmtrocar 1516. The implantable interface 1524 is depicted with foldablewings 1534 through which suture or other fasteners (such as helicalcoils) may be placed. The foldable nature of the wings 1534 allow theimplantable interface 1524 to be placed completely through the trocar1516. Alternatively, the implantable interface 1524 does not havefoldable wings 1534, and instead has a separate bracket or mount whichis configured for securing the implantable interface to the patient1500.

FIG. 106 depicts an alternative method of placing the obesity controlsystem into the abdominal cavity. In this embodiment, the implantableinterface 1524 is placed first, for example by pushing it through the 12mm trocar 1516 with the 5 mm grasper 1532. The 5 mm grasper 1532 is thenused to place the obesity control system into the abdominal cavity 1510by manipulation of the drive transmission 1522 through the 12 mm trocar1516. Once the obesity control system is placed in the abdominal cavity,the restriction device 1520 is placed around the stomach at the junctionof the stomach and esophagus, and one or more gastrogastric sutures areplaced to secure the stomach around the restriction device 1520.

FIG. 107 depicts the obesity control system in position to be placedcompletely intra-abdominally in the patient 1500, with the implantableinterface located in the lower abdominal area. FIG. 108 also depicts theobesity control system in position to be placed completelyintra-abdominally, behind the lower portion of the sternum, and areaknown as xiphoid. Intra-abdominal placement has many advantages.

First, the patient will not be able to feel or be bothered by theimplantable interface 1524, as they sometimes are in subcutaneousplacements. Second, by securing the entire device intra-abdominallythere is less time wasted manipulating the skin, fat, and fascia at theentry site and thus, a lower risk of infection. Third, it is possible toplace the device with little or no incision at the skin because, asexplained below, the attachment of the implantable interface 1524intra-abdominally does not require a large surface area for manipulationfrom the outside.

FIG. 109 demonstrates the configuration of an obesity control systemthat is placed when using the subcutaneous attachment of the implantableinterface 1524. A tunnel is made in order to expose the fascia 1536which covers the muscle 1538, and to which the implantable interface1524 is attached. FIG. 110 depicts the obesity control system after ithas been completely secured in the subcutaneous method First and secondsutures 1542, 1544 close the skin over the implantable interface 1524.In FIG. 110 , the implantable interface 1524 has been attached to thefascia 1536 with helical screws 1540

Returning to the embodiment that utilizes a completely intra-abdominalplacement of the obesity control system, FIG. 111 depicts the use of asuture passer 1546 having an actuator handle 1550 and a grasping tip1552 configured for securing suture 1548. The suture 1548 is grasped bythe grasping tip 1552 via manipulation of the actuator handle 1550 Thesuture 1548 is then passed through a small opening in the skin (e.g., atrocar hole), and the sharp grasping tip 1552 of the suture passer 1546is forced through the remaining abdominal wall and through a hole in thefoldable wing 1534 of the implantable interface 1524 (as seen in FIG.112 ).

The implantable interface 1524 can be held stationary by using aseparate grasper (not pictured) The suture 1548 is released, once it haspassed through the hole in the foldable wing 1534 and into the abdominalcavity 1510. The suture passer 1546 is then removed and the suture isleft in place as seen in FIG. 113 The suture passer 1546 is theninserted through the abdominal wall at another site and through anotherhole of a second foldable wing 1534. The suture 1548 is now grasped inthe inside by the grasping tip 1552, as depicted in FIG. 114 This newlygrasped end of the suture is then pulled back through the hole in thesecond foldable wing 1534 and then pulled out through the abdominalwall. The suture passes 1546 is now released from the suture 1548 viamanipulation of the actuator handle 1550. The suture 1548 now loops intoand out of the abdominal cavity and secures the implantable interface1524 through two foldable wings 1534, as seen in FIG. 115 . This may berepeated with other pieces of suture, for example if the implantableinterface 1524 has four foldable wings 1534 instead of two. As shown inFIG. 116 , the suture 1548 is then tied off in a knot 1554, to securethe implantable interface 1524 within the abdominal cavity, and the skinis closed with more suture 1556.

In the above-described subcutaneous and intra-abdominal methods forimplanting and securing an obesity control system, it is common forthere to be several 5 mm trocars in addition to the one 12 mm trocardepicted. For example, a 5 mm trocar for placing a liver retractor, andtwo or more other 5 mm trocars through which various surgical tools areplaced (e.g., graspers, cutters, and cautery tools). FIG. 117 describesan alternative method of performing implantation and securement of anobesity control system, using a single trocar 1558. Trocars,unfortunately, can leave scars on the skin and can also causeport-surgical pain. Having a single trocar and thus single site oraccess passageway through the skin, will cause less scarring and lesspost-surgical pain. In addition, while this site may be located anywhereon the skin of the body (e.g., the abdominal wall), it may also beplaced in the naval 1514 area, so that the scar is not noticeable. Inaddition, the single site may be chosen within the rectum or vagina, sothat the scar does not show. These two sites allow access into theabdominal cavity, as does an additional site through the mouth andstomach FIG. 117 depicts the single site as having been chosen throughthe naval 1514 general area although, as explained above, other sitelocations may also be used.

The single trocar 1558 has three (3) 5 mm lumens 1560, 1562, 1564.Turning to FIG. 118 , a 5 mm laparoscope 1566 is placed through lumen1562. The laparoscope 1566 comprises a distal end 1570 and a proximalend 1568. including a camera. A 5 mm grasper 1572 having a grasping tip1576 and a manipulating handle 1574 is placed through lumen 1564 andinto abdominal cavity 1510. The grasping tip 1576 of the 5 mm grasper1572 carries a liver retraction magnet 1580 having clamp 1578 securedthereto. The 5 mm grasper 1572 is configured to grasp the clamp 1578 ina manner so that when the clamp 1578 and magnet 1580 are delivered tothe liver 1504, the clamp 1578 is open.

While viewing on laparoscopy, the clamp 1578 is released by the 5 mmgrasper 1572, causing it to engage the liver 1504, securing the magnet1580 to the liver 1504. The 5 mm grasper 1572 may also be used toretract the liver 1504 so that it is out-of-the-way from the surgicalprocedure in the area of the upper stomach. An external magnet 1582having a handle 1584 is placed on the outside of the upper abdomen andan attraction force, shown be field 1586 in FIG. 119 , maintains theexternal magnet 1582 and the magnet 1580 together. The liver 1504 is nowretracted and the 5 mm grasper 1572 can be removed completely, or usedfor other purposes.

Turning now to FIG. 120 , the single trocar 1558 is removed and theobesity control system is inserted through the tract made by the trocar1558 The jaws 1590 of a forceps 1588 are used to grip the obesitycontrol system as it is inserted into the abdominal cavity 1510. Oncethe obesity control system is placed completely within the abdominalcavity 1510, the trocar 1558 is replaced and the remaining portion ofthe implant procedure can be viewed through the laparoscope 1566 as seenin FIG. 121 , while ports 1560 and 1564 are used for the placement ofvarious instruments. The creation of a tunnel, for example in the parsflaccida method, can be performed with an articulating dissection toolThe creation of gastrogastric attachment, typically made using suture inmost gastric restriction device procedures, presents a challenge in thissingle trocar method, because of the absence of good separation between,for example, two graspers being used to suture the stomach wall in twoplaces, around the restriction device

An alternative apparatus is shown in FIG. 122 and is configured to beplaced through one of the ports of the trocar 1558. The gastricrestriction device 1602 is shown in-place around the stomach 1600,creating a small pouch 1610 just below esophagus 1604. The wall of anupper portion 1606 and a lower portion 1608 adjacent the gastricrestriction device 1602 are to be secured to each other Instead ofsuturing the upper portion 1606 and the lower portion 1608 together, atool 1618 having a shaft 1612 and a handle 1622 grips a releasable clip1614. The tool 1618 is inserted through a part of the trocar 1558 andthe releasable clip 1614 is advanced to close proximity of the upperportion 1606 and lower portion 1608. Proximal grip 1616 is secured tothe lower portion 1608 by manipulating the first trigger 1624. The lowerportion 1608 is then manipulated close to the upper portion 1606 andthen distal grip 1617 is secured to upper portion 1606 by manipulatingsecond trigger 1626. The releasable clip 1614 is released at separationpoint 1628 by pressing release button 1620. The tool 1618 can be torquedas needed, and also, an articulation 1630 can be controlled by slide1632 on the handle 1622. This allows the desired orientation to beachieved at each step. A second releasable clip may be attached to thetool 1618 (or a different tool) and a parallel attachment can be made.

It should be understood that in case of emergency, the entire gastricrestriction device may be withdrawn from the patient via the trocar1516, 1558. This includes a 12 mm trocar such as trocar 1516 in additionto a multi-lumen trocar 1558.

While embodiments of the present invention have been shown anddescribed, various modifications may be made without departing from thescope of the present invention. The invention, therefore, should not belimited, except to the following claims, and their equivalents.

What is claimed is:
 1. A system comprising: an adjustable implantconfigured for implantation within a subject, the adjustable implantcomprising: a housing; a magnet disposed within the housing andconfigured for rotation about an axis of rotation; and a drivetransmission operatively coupled to the magnet and configured to alter adimension of the adjustable implant, and an external adjustment deviceconfigured to be positioned outside the subject and to interact with theadjustable implant, the external adjustment device comprising: a motor;at least one permanent magnet configured to rotate in response toactuation of the motor; an encoder configured to monitor positionalinformation of the at least one permanent magnet; and a drive controlcircuit configured to receive an input signal from the encoder thatcorresponds to the positional information of the at least one permanentmagnet and actuate operation of the motor based at least in part on theinput signal, thereby rotating the at least one permanent magnet,wherein rotation of the at least one permanent magnet effectuatesrotation of the magnet of the adjustable implant and alters thedimension of the adjustable implant.
 2. The system of claim 1, whereinthe drive transmission comprises a lead screw operatively coupled to themagnet and a nut moveable along a length of the lead screw.
 3. Thesystem of claim 1, wherein the encoder is an optically-based encoder oran audio-based encoder.
 4. The system of claim 1, wherein the encodercomprises a light source and a light receiver operatively coupled to thelight source.
 5. The system of claim 1, wherein the at least onepermanent magnet comprises a first permanent magnet having a first axisof rotation and a second permanent magnet having a second axis ofrotation different from the first axis of rotation.
 6. The system ofclaim 5, wherein the input signal corresponds to an angular position ofone of the first and second permanent magnets.
 7. The system of claim 1,wherein the drive control circuit is configured to control at least oneof a speed and a rotational direction of the motor.
 8. The system ofclaim 1, wherein the drive control circuit is further configured toreceive a drive instruction for adjusting the adjustable implant.
 9. Thesystem of claim 8, wherein the drive instruction comprises a numericalvalue representing an adjusted dimension of the adjustable implant. 10.The system of claim 8, wherein the drive instruction comprises anumerical value representing an increase or a decrease in the dimensionof the adjustable implant.
 11. The system of claim 10, wherein theincrease or the decrease in the numerical value representing thedimension of the adjustable implant is proportional to a number of turnsof the magnet of the adjustable implant.
 12. The system of claim 1,wherein the drive control circuit is operatively coupled to one or moreof a display, a keyboard, an input device for inputting a numericalvalue representing an adjusted dimension of the adjustable implant. 13.The system of claim 1, wherein the drive control circuit comprises aprogrammable logic controller.
 14. The system of claim 1, furthercomprising a feedback device operatively coupled to the magnet of theadjustable implant and configured to produce a feedback indicative ofinformation relating to rotation of the magnet about the axis ofrotation.
 15. A system comprising: an adjustable implant configured forimplantation within a subject, the adjustable implant comprising: ahousing; a magnetically responsive unit disposed within the housing andconfigured to generate rotation about an axis of rotation; and a drivetransmission operatively coupled to the magnetically responsive unit andconfigured to alter a dimension of the adjustable implant in response tothe rotation, and an external adjustment device configured to bepositioned externally relative to the subject and to interact with theadjustable implant, the external adjustment device comprising: anactuating member; at least one permanent magnet configured to rotate inresponse to actuation of the actuating member; means for monitoringpositional information of the at least one permanent magnet andproviding an input signal that corresponds to the positional informationof the at least one permanent magnet; and a drive control circuitconfigured to receive the input signal and actuate operation of theactuating member based at least in part on the input signal, therebyrotating the at least one permanent magnet, wherein rotation of the atleast one permanent magnet effectuates rotation of the magneticallyresponsive unit and alters the dimension of the adjustable implant. 16.The system of claim 15, wherein the magnetically responsive unitcomprises a magnet.
 17. The system of claim 15, wherein the magneticallyresponsive unit comprises a resonance beam, and the at least onepermanent magnet comprises a magnet having a resonating frequencyidentical to a resonating frequency of the resonance beam.
 18. Thesystem of claim 15, wherein the actuating member is a motor and thedrive control circuit is configured to control at least one of a speedand a rotational direction of the motor.
 19. The system of claim 15,wherein the drive control circuit is further configured to receive adrive instruction for adjusting the adjustable implant.
 20. The systemof claim 19, wherein the drive instruction comprises a numerical valuerepresenting an adjusted dimension of the adjustable implant.